66-million-year-old deathbed linked to dinosaur-killing meteor

Fossil site preserves animals killed within minutes of meteor impact

University of California – Berkeley

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A meteor impact 66 million years ago generated a tsunami-like wave in an inland sea that killed and buried fish, mammals, insects and a dinosaur (Triceratops), the first victims of a cataclysm that led to Earth’s last mass extinction. The death scene from within an hour of the impact has been excavated at an unprecedented fossil site in North Dakota. Credit: Graphic courtesy of 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.

“This is the first mass death assemblage of large organisms anyone has found associated with the K-T boundary,” said DePalma, curator of paleontology at the Palm Beach Museum of Natural History in Florida and a doctoral student at the University of Kansas. “At no other K-T boundary section on Earth can you find such a collection consisting of a large number of species representing different ages of organisms and different stages of life, all of which died at the same time, on the same day.”

In a paper to appear next week in the journal Proceedings of the National Academy of Sciences, he and his American and European colleagues, including two University of California, Berkeley, geologists, describe the site, dubbed Tanis, and the evidence connecting it with the asteroid or comet strike off Mexico’s Yucatan Peninsula 66 million years ago. That impact created a huge crater, called Chicxulub, in the ocean floor and sent vaporized rock and cubic miles of asteroid dust into the atmosphere. The cloud eventually enveloped Earth, setting the stage for Earth’s last mass extinction.

“It’s like a museum of the end of the Cretaceous in a layer a meter-and-a-half thick,” said Mark Richards, a UC Berkeley professor emeritus of earth and planetary science who is now provost and professor of earth and space sciences at the University of Washington.

Richards and Walter Alvarez, a UC Berkeley Professor of the Graduate School who 40 years ago first hypothesized that a comet or asteroid impact caused the mass extinction, were called in by DePalma and Dutch scientist Jan Smit to consult on the rain of glass beads and the tsunami-like waves that buried and preserved the fish. The beads, called tektites, formed in the atmosphere from rock melted by the impact.


Tsunami vs. seiche

Richards and Alvarez determined that the 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 impact 3,000 kilometers away, if it didn’t peter out before then. Their reasoning: The tektites would have rained down within 45 minutes to an hour of the impact, unable to create mudholes if the seabed had not already been exposed.

Instead, they argue, seismic waves likely arrived within 10 minutes of the impact from what would have been the equivalent of a magnitude 10 or 11 earthquake, creating a seiche (pronounced saysh), a standing wave, in the inland sea that is similar to water sloshing in a bathtub during an earthquake. Though large earthquakes often generate seiches in enclosed bodies of water, they’re seldom noticed, Richards said. The 2011 Tohoku quake in Japan, a magnitude 9.0, created six-foot-high seiches 30 minutes later in a Norwegian fjord 8,000 kilometers away.

“The seismic waves start arising within nine to 10 minutes of the impact, so they had a chance to get the water sloshing before all the spherules (small spheres) had fallen out of the sky,” Richards said. “These spherules coming in cratered the surface, making funnels — you can see the deformed layers in what used to be soft mud — and then rubble covered the spherules. No one has seen these funnels before.”

The tektites would have come in on a ballistic trajectory from space, reaching terminal velocities of between 100 and 200 miles per hour, according to Alvarez, who estimated their travel time decades ago.

“You can imagine standing there being pelted by these glass spherules. They could have killed you,” Richards said. Many believe that the rain of debris was so intense that the energy ignited wildfires over the entire American continent, if not around the world.

“Tsunamis from the Chicxulub impact are certainly well-documented, but no one knew how far something like that would go into an inland sea,” DePalma said. “When Mark came aboard, he discovered a remarkable artifact — that the incoming seismic waves from the impact site would have arrived at just about the same time as the atmospheric travel time of the ejecta. That was our big breakthrough.”

At least two huge seiches inundated the land, perhaps 20 minutes apart, leaving six feet of deposits covering the fossils. Overlaying this is a layer of clay rich in iridium, a metal rare on Earth, but common in asteroids and comets. This layer is known as the K-T, or K-Pg boundary, marking the end of the Cretaceous Period and the beginning of the Tertiary Period, or Paleogene.

Iridium

In 1979, Alvarez and his father, Nobelist Luis Alvarez of UC Berkeley, were the first to recognize the significance of iridium that is found in 66 million-year-old rock layers around the world. They proposed that a comet or asteroid impact was responsible for both the iridium at the K-T boundary and the mass extinction.

The impact would have melted the bedrock under the seafloor and pulverized the asteroid, sending dust and melted rock into the stratosphere, where winds would have carried them around the planet and blotted out the sun for months, if not years. Debris would have rained down from the sky: not only tektites, but also rock debris from the continental crust, including shocked quartz, whose crystal structure was deformed by the impact.

The iridium-rich dust from the pulverized meteor would have been the last to fall out of the atmosphere after the impact, capping off the Cretaceous.

“When we proposed the impact hypothesis to explain the great extinction, it was based just on finding an anomalous concentration of iridium — the fingerprint of an asteroid or comet,” said Alvarez. “Since then, the evidence has gradually built up. But it never crossed my mind that we would find a deathbed like this.”

Key confirmation of the meteor hypothesis was the discovery of a buried impact crater, Chicxulub, in the Caribbean and off the coast of the Yucatan in Mexico, that was dated to exactly the age of the extinction. Shocked quartz and glass spherules were also found in K-Pg layers worldwide. The new discovery at Tanis is the first time the debris produced in the impact was found along with animals killed in the immediate aftermath of the impact.

“And now we have this magnificent and completely unexpected site that Robert DePalma is excavating in North Dakota, which is so rich in detailed information about what happened as a result of the impact,” Alvarez said. “For me, it is very exciting and gratifying!”

Tektites

Jan Smit, a retired professor of sedimentary geology from Vrije Universiteit in Amsterdam in The Netherlands who is considered the world expert on tektites from the impact, joined DePalma to analyze and date the tektites from the Tanis site. Many were found in near perfect condition embedded in amber, which at the time was pliable pine pitch.

“I went to the site in 2015 and, in front of my eyes, he (DePalma) uncovered a charred log or tree trunk about four meters long which was covered in amber, which acted as sort of an aerogel and caught the tektites when they were coming down,” Smit said. “It was a major discovery, because the resin, the amber, covered the tektites completely, and they are the most unaltered tektites I have seen so far, not 1 percent of alteration. We dated them, and they came out to be exactly from the K-T boundary.”

The tektites in the fishes’ gills are also a first.

“Paddlefish swim through the water with their mouths open, gaping, and in this net, they catch tiny particles, food particles, in their gill rakers, and then they swallow, like a whale shark or a baleen whale,” Smit said. “They also caught tektites. That by itself is an amazing fact. That means that the first direct victims of the impact are these accumulations of fishes.”

Smit also noted that the buried body of a Triceratops and a duck-billed hadrosaur proves beyond a doubt that dinosaurs were still alive at the time of the impact.

“We have an amazing array of discoveries which will prove in the future to be even more valuable,” Smit said. “We have fantastic deposits that need to be studied from all different viewpoints. And I think we can unravel the sequence of incoming ejecta from the Chicxulub impact in great detail, which we would never have been able to do with all the other deposits around the Gulf of Mexico.”

“So far, we have gone 40 years before something like this turned up that may very well be unique,” Smit said. “So, we have to be very careful with that place, how we dig it up and learn from it. This is a great gift at the end of my career. Walter sees it as the same.”

###

Co-authors with DePalma, Smit, Richards and Alvarez are David Burnham of the University of Kansas, Klaudia Kuiper of Vrije Universiteit, Phillip Manning of Manchester University in the United Kingdom, Anton Oleinik of Florida Atlantic University, Peter Larson of the Black Hills Institute of Geological Research in South Dakota, Florentin Maurrasse of Florida International University, Johan Vellekoop of Katholieke Universiteit Leuven in Belgium and Loren Gurche of the Palm Beach Museum of Natural History.

From EurekAlert!

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147 thoughts on “66-million-year-old deathbed linked to dinosaur-killing meteor

  1. Interesting stuff but these days the cynic in me looks for the subtext in this type of story. Lately this is frequently about the latest “mass extinction” which is often claimed but not substantiated.

    • Right, …. claimed but not substantiated.

      Publishing this …..
      First-confirmed occurrence of a lambeosaurine dinosaur found on Alaska’s North Slope
      ….. a second time, …..will not make me think it is more science factual or believable.

      Now I believe they found what they found, ….. but I don’t believe their interpretation of what they found.

      IMLO, they have assumingly included everything but the “kitchen sink” in hopes of convincing both peers and public.

        • That coming devastation is even more amazing considering we are already 2/3rds there, with the devastation coming with the final 1/2 degree C.

      • And by the way, ,…… that 66 million years old asteroid strike of the Yucatán peninsula locale was far, far more powerful that you imagined, to wit:

        The following excerpted from this article published in The New Yorker magazine and titled The Day the Dinosaurs Died.

        Within two minutes of slamming into Earth, the asteroid, which was at least six miles wide, had gouged a crater about eighteen miles deep and lofted twenty-five trillion metric tons of debris into the atmosphere. …… The asteroid was vaporized on impact. Its substance, mingling with vaporized Earth rock, formed a fiery plume, which reached halfway to the moon before collapsing in a pillar of incandescent dust. Computer models suggest that …. About seventy-five per cent of all species went extinct. More than 99.9999 per cent of all living organisms on Earth died, and the carbon cycle came to a halt. ….. etc., etc.

        One of the central mysteries of paleontology is the so-called “three-­metre problem”.

        In a century and a half of assiduous searching, almost no dinosaur remains have been found in the layers three metres, or about nine feet, below the KT boundary, a depth representing many thousands of years. Consequently, numerous paleontologists have argued that the dinosaurs were on the way to extinction long before the asteroid struck, owing perhaps to the volcanic eruptions and climate change. Other scientists have countered that the three-metre problem merely reflects how hard it is to find fossils. Sooner or later, they’ve contended, a scientist will discover dinosaurs much closer to the moment of destruction.

        And there ya have it folks, …… no dinosaurs to be found when that famous asteroid struck the Yucatán peninsula locale.

          • Yes, quite a bit of hyperbole and fuzzy reporting in the New Yorker article. I’m surprised a Berkeley news release is so clear and informative. Seems more likely after reading this that the site may have resulted from whatever threw up all those tektites. Still not clear to me that living non-avian dinosaurs were actually there at the same moment. I also wonder why there would be only two seiches, although I suppose they must decrease in amplitude rather quickly.

        • Some “food” for thought, …… for those capable of thinking for themselves.

          The Age of the Dinosaurs is the period in geologic time from about 252 Mya to about 66 Mya and includes the Triassic, Jurassic and the Cretaceous Periods and which is plainly denoted on this Atmospheric CO2 & Average Global Temperature proxy graph, to wit:
          http://www.dandebat.dk/images/1365p.jpg

          And as one can easily see on said graph, the correlation between the “rise and fall” of atmospheric CO2 pretty much coincides EXACTLY with the “rise and fall” of the Age of the Dinosaurs.

          And the quantity of food required for nourishing and maintaining said “rise of the dinosaurs” was highly dependent upon the 1,600+ ppm of atmospheric CO2 …. and when the CO2 started its decrease below 1,600 ppm at around 100 Mya the dinosaurs began dying off due to starvation.

          No asteroid strike needed, ….. lack of atmospheric CO2 did the job.

          Cheers, ….. Sam the evolutionary Biologist 😊

    • Yes, and the “killing fields” are in Cambodia and have nothing to do with fossils or geology.

  2. I’m worried that if we don’t have another asteroid impact soon they will start running short of iridium to make replacement nibs for my fountain pen. Is there anything else to worry about with this?

    • My model predicts more dinosaur-killer asteroid impacts if CO2 keeps increasing in the atmosphere.

      Where do I apply for my grant money?

        • If my grant money came from the dinosaurs,

          then I would be one of those deplorable deniers funded by dirty “fossil fuel” money.

      • Pillage: You’re talking psuedo-science, CO2 attracting asteroids. However, if you consider the impact as increasing atmospheric CO2 and the increased CO2 causing the last mass extinction, then you get the grant and a piece of a nobel! Ya can’t waste a cataclysmic event by not conjecturing CO2 as the direct cause of flaming glass rain.

        • You couold always follow the path of CO2 increasing atmospheric temperatures…
          Warmer atmosphere = puffier atmosphere…
          Puffier atmosphere extends a little farther into space…
          Extended envelope surface has a greater chance to grab the closely passing asteroid…
          Larger asteroids/meteors have better opportunity to be redirected to the surface…

          More CO2 = greater chance of Extinction Level Event
          /snark, snark, snark

  3. I had an encounter with Professor Luis Alvarez in the 90’s. We had a Yosemite Valley group camp site right next to the Prof’s geology field trip site. That was OK except one tent with a pair of female insomniacs who with pretty loud voices raked every detail of their young lives deep into the night. I asked them several times to desist but after a few minutes their inane conversation would spring back into life like a Tesla fire. Finally around 3AM I located the professor on the far side of their site. I really hated waking him but I was at wits end. He was very polite, and after listening for maybe 10 seconds he sighed, said this goes on EVERY night, got up and went over and told them sharply to knock it off. They did and I and my compadres got a few hours of uninterrupted sleep.

  4. Sobering. There prb’ly wasn’t anywhere on the surface that would’ve escaped the effects. Being underground would still be subject to the earthquakes.

    • My understanding, since I live in a serious earthquake zone and drive through fairly long tunnels (to and from Alameda Island) frequently and, consequently, read about these things, is that earthquake damage doesn’t happen in such underground structures. A bit tangential to the topic, but if anyone knows more about this ….. ?

      • Buildings above ground can wave about in the air and move. Masonry doesn’t like to move.
        There is nowhere for displacement to occur underground unless you are directly on a displacement zone (rift). You’ll feel the force but everything will be mostly held in place.

    • Things were perhaps not quite as bad in Antarctica (which was temperate at the time). Several of the surviving animal lineages seem to have come from there.

      • And presumably what would become Australia and India and maybe southern South America and Africa? A hunk of Gondwanan lands being spared the over wrought Armageddon in the New Yorker article would help explain some distributions I’m interested in. On the other hand, the fossil amber I’ve seen from 90 mya from Alberta has mostly extant families and some genera, so I wonder how bad it would have been even there – not that far from North Dakota.

        • India would probably have been very badly affected since it was antipodal to Chicxulub and the density of ejecta would therefore have been very high there.
          It is also known that the seismic effects of large impacts are focussed near the antipodal point (e. g. Caloris impact on Mercury) and it has been suggested that Chicxulub may have triggered the main pulse of the Deccan eruptions. The two events cannot be separated by age, any difference falls within the margin of error. Note that the earlier pulses of the Deccan eruptions which are often supposed to have caused dinosaur extinction worldwide didn’t even eliminate dinosaurs from the (isolated) Indian continent. There are dinosaur fossils in the “intertrappan beds”, between basalt layers.

    • “That means that the first direct victims of the impact are these accumulations of fishes.”

      hmm…I might think the creatures at the impact site might have been the first direct victims of the impact.
      Everything else is a subsequent effect of the impact.

    • Joseph,
      I agree! This a marvelous discovery and a treasure trove of priceless K-T boundary information!
      I’m surprised more commenters here are cynical, rather than inspired by this bounty of paleo-science.

    • Yes. I found out about this article yesterday in Judith Curry’s tweeter. It is long and very good.

      There is a lot of caution in the field because the claim that the finding can be dated to exactly within an hour of the impact is a big claim. Nevertheless what it is clear is that it is a magnificent finding with lots of new species and a big argument about the meteorite finishing the dinos. So far I was more inclined to the Deccan traps hypothesis.

      The history of DePalma is most interesting, and quite intriguing. After 15 years in the field and several famous advisors he hasn’t got his PhD. In my country that is inconceivable. You put your four years of effort and you get it.

  5. … this was a killing field laid down soon after the asteroid impact that eventually led to the extinction of all ground-dwelling dinosaurs.

    Didn’t kill all the amphibians, fish, mammals, marsupials, monotremes, birds, snakes, crocodiles, turtles, lizards, arthropods, snails etc., but it did kill all the dinosaurs. Pretty darn selective asteroid. There may have very well been an asteroid strike, but disease did in the dinosaurs, nothing else would have been that selective.

    You heard it here first.

    • I’m kind of glad that I don’t have to look over my shoulder much of the time, or worse worry about a pterodactylus swooping down to pick up me or a family member.

    • Didn’t kill all the dinos. They are still among us with their feathers. Look at the eyes and the beak of an eagle and you can see that their spirit is alive. They just evolved.

      • Asteroids killed the dinosaurs is just as much group think as CO2 is on track to cause a climate catastrophe.

        • Don’t forget…Most Dino’s were quite large and likely top of the food chain preditors and consumers and required large caloric intake daily to survive. Most of the others, mammals etc..were smaller and required far less food to survive. Dino’s required tens to hundreds of pounds of food daily depending on type, size and maturity. Once the majority of Vegitation was burned off, the large herbivores had no food and died off. Similar for the large carnivores. once the large herbivores were gone or decaying to far to consume, the large carnivores also ran out of food. The only thing that could survive are those animals that had far lesser dietary requirements and could survive on sprouting shrubs or consuming very small animals.

          • Bryan A April 1, 2019 at 10:26 am
            Don’t forget…Most Dino’s were quite large…

            Not so:
            “…the idea that non-avian dinosaurs were uniformly gigantic is a misconception based in part on preservation bias, as large, sturdy bones are more likely to last until they are fossilized. Many dinosaurs were quite small: Xixianykus, for example, was only about 50 cm (20 in) long.
            https://en.wikipedia.org/wiki/Dinosaur

          • Steve Case
            That I have found, only 30 species of dinosaur fossils exist front the Cretaceous Period. 25 of them are larger than 12′ and 15 of those are larger than 25′. 4 are around 6′ and one, the Microrapter was 24″. Of all, the microrapter had the best chance of survival. Although some fossilized specimens have been discovered with potentially fossilized stomach contents consisting of small mammals about the size of mice or voles, the species existed in the early Cretaceous around 120 mya but vanished from the fossil record long before the K-T mass extinction event

          • The one you mentioned “Xixianykus” isn’t part of my list. I shall have to add it and thank you for bringing it to my attetion. Tis most unfortunate though that the skull wasn’t found with the rest of the remains. This surely would have determined it to be a separate species and not perhaps a juvinile Xixiasaurus.
            Oh Boy a new one to look into.

        • Steve, it killed 99+% of all individual creatures!!! Certainly the large animals were most prone. Some small animals could and did survive, possibly taking cover, the sea would lose fewer than the land. A global rainstorm of hot glass! Man! The smaller animals would be able to feed on the dead, herbivores would have difficulties, sun blocked out for months(?), fine dust of glass, rock, smoke. What do you think it would take? Disease hasnt had a hand in mass extinctions. Diseases affect specific creatures (dogs, horses.
          …. dont get the flu). How come we don’t find fossils of large dinosaurs after the Cretaceous and these creatures populated from Antarctica to the Arctic and around the world – suggests a sudden global cause.

          Steve, this was a bigger deal than most think.

          • Actually the effects were if anything worse in the sea. Probably because the photosynthesizing organisms there are mostly microscopic so there is an abrupt collapse of food chains as soon as sunlight stops.

            On land small animals could survive by eating each other and the remains of dead animals and plants until surviving roots and seeds got photosynthesis started again. Freshwater organisms did best of all, they were thermally buffered by water and freshwater food chains are to a considerable extent based on detritus from land even in normal times. Note that crocodiles were the only large archosaurs to survive.

          • Among land animals, those that ate storable foods like seeds and nuts, or animals with low metabolisms like amphibians and reptiles, and those that could hibernate, were best set to survive it. Small mammals are great at stockpiling food in their dens.

      • The way those chickens look at me, I have no doubt about it!

        Thanks for this article–coolest thing I’ve read all week!

    • A disease that kills all the dinosaurs except the ones that evolved into other things? And didn’t kill all reptiles but only reptiles? And how was it communicated globally? And what, it literally didn’t leave any resistant dinosaurs behind to repopulate? It killed every single one and it infected every single one?

      Sorry, disease just does not remotely seem possible.

    • I’m sure that the death rate among surviving species must have been pretty high also. A small, fast breeding SPECIES could survive the impact even if 90+% of the individuals of that species were killed.

    • It killed all the megafauna by disrupting their food supplies. Smaller critters survived because they needed less food

    • No mention as to whether the meteor in question had gotten the proper EPA studies and filed the proper forms with the multitude of government agencies.

    • Dinosaurs (except birds), almost all birds (only a few species survived), all mosasaurs, plesiosaurs, and pterosaurs, (those are not dinosaurs), most synapsids (a few eutheria, metatheria, monotremes and multituberculates survived), all ammonites, all rudists etc

      Must have been an extremely peculiar disease.

      • Must have been an extremely peculiar disease.

        Must have been an extremely peculiar asteroid.

        • That’s just it Steve. The asteroid isnt selective. Hey we’ve recently had a few scary ones pass between the earth and the moon. You know they are out there, right.

          • Gary Pearse April 1, 2019 at 3:16 pm
            That’s just it … The asteroid isnt selective.

            So why did it select just the dinosaurs for complete extinction?

          • It DIDN”T just select the dinosaurs. It immediately killed off a large percentage of everything. Small, quickly breeding creatures could quickly make up the difference when their numbers dropped 90%. Notice how flies proliferate each spring despite suffering 99% + casualties each fall?

            On the other hand, large slower breeding creatures, like the dinosaurs, wouldn’t recover as fast. There’d also be the immediate problem of staying alive until plants could replenish the terrain. The fewer remaining large creatures would starve, while smaller creatures could scavenge in the interval.

        • “Must have been an extremely peculiar asteroid.”

          Probably not, though opinions are divided whether it was a L-chondrite or a carbonaceous chondrite.

      • All dinosaurs (even the small ones) except birds, all mosasaurs but not varanids … strange disease indeed, but what survived always seemed strange. Plants from seeds is reasonable, but others like crocodilians etc. seem very ad hoc in their explanations. When I was a child I thought that when I died and went to heaven the first question I would ask God would be ‘What happened to the dinosaurs?’ Now I think I’d ask how did the others survive.

    • Think.
      Dinosaurs were essentially flightless birds.
      Think.
      Time’s up.
      Mammals, likely rodents, killed off the flightless birds.

  6. At first glance this is entirely possible. The P-waves travel very fast, up to 8/km/sec in the crust and up to 13/km/sec in the upper mantle, so the timing could work out. The rain of tektites is another matter, it is hard to imagine them not being influenced by winds as they are very low density and not very large. However, sounds like good work from the hands-on in the field to writing up the story.

  7. I still can’t help thinking that the Tektites would have cooled too much to cause fires…. They would be falling for several minutes at ordinary terminal velocities…. Globules of molten steel cool very fast and falling from a hundred kilometers up, they’d cool and be no fire risk.

    A very interesting find nonetheless though.

    • Not necessarily. The smallest tektites would have vaporized during re-entry. Somewhat larger ones will have reached terminal velocity before impact and cooled while still larger ones would impact at high speed and still be very hot. And a few hot ones per square mile would be quite enough to cause very extensive wildfires in any reasonably dry areas. And really large fragments could ignite large areas by radiation alone. Google “libyan desert glass”.

      • What will be causing the tektites to vaporize during reentry? They would not have anywhere near the reentry velocities to vaporize. Ate the apex of their trajectory they will have 0 vertical velocity.
        as they fall they will pick up speed due to gravity, but long before they reach any appreciable speed the air will slow them down until they reach maximum (terminal velocity) when gravitational forces balance aerodynamic drag. Merely falling from space from the edge of space (62 miles up) will never achieve burn-up speeds. this was recently demonstrated by Max Baumgartner when he leapt from a balloon near the edge of space. He reached supersonic speeds, but that is relative with altitude. At the altitudes he reached Mach 1 there isn’t much air and hence very little drag and very little aerodynamic heating. As soon as he altered his descent attitude from a head down dive to a higher drag attitude (belly down) he slowed to much lower terminal velocity.

        No meteorite (one that actually hits) in recorded history has ever caused a ground fire.

      • Of course they would have re-entry speeds. And of course they would not have zero velocity at the apex of their trajector. A tektite is in effect a ballistic missile.

        The warheads of early IRBM:s of the 50’s, which operated over ranges comparable to the distance from Yucatan to North Dakota reached temperatures of 12,000 F in the stagnation zone:

        https://www.nasa.gov/sites/default/files/695726main_ComingHome-ebook.pdf

        And tektites don’t have optimal shapes for re-entry either.

        “No meteorite (one that actually hits) in recorded history has ever caused a ground fire”

        That is because no large meteorite has “actually hit” in recorded history. But it may actually have happened:

        https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1945-5100.1946.tb00081.x

        And large meteors certainly can start fires. If it can melt desert sands it can certainly light fires:

        https://www.meteorite-times.com/atacamaites-central-atacama-desert-chile/

        • This makes more sense. So the tektites were terminal velocity from extra-atmosphere. I was reading the part about them and going, “How?”

          • Quite apart from the supersonic shock wave, the impact probably made quite a splash in the atmosphere, so the tektites were falling through rarified air that was rushing with considerable velocity in the same direction they were going, thus not slowing them nearly as much as a fall through a stationary thick atmosphere.

  8. The article says: “the Earth’s last mass extinction”. I fear they are wrong. It may just have been the latest.

    • Communication is difficult, especially when you think it is occurring.
      Since there haven’t been any mass extinctions between then and now it is colloquially correct to say it was the “last mass extinction” wherein “last” means directly previous to now. You are assuming a different interpretation of “last” meaning “final”.

  9. What an astounding story.

    All credit to DePalma for his initial piecing-together of what he had found, and for then seeking out and bringing on-board a stellar team of experts. Such acuity and (dare I say it) humility seems rarely to feature in the competitive and bitchy field of earth/life sciences! See how the “competition” is already whining about “lack of access” to the site.

    He is only a 30-something doctoral student. He should be granted his doctorate by acclamation: he has certainly earned it.

    What great strides are being made right now in understanding Earth sciences and pre-history. Don’t forget that this discovery comes only months after the revelation of the Greenland Hiawatha Glacier crater, and its potential implications for the Younger Dryas extinction event!

    • Care to expand on that for us? I’m not feeling April fooled by this (especially having read other articles on it in the past few days).

  10. Okay, where are the folks who were bitchin’ at our kind host about “not enough science” during the AOC comments? Your cup is half-full here, not half-empty. 😉

  11. There seems to be a large number of assumptions in their analysis.
    e.g.;

    ““Tsunamis from the Chicxulub impact are certainly well-documented, but no one knew how far something like that would go into an inland sea,” DePalma said. “When Mark came aboard, he discovered a remarkable artifact — that the incoming seismic waves from the impact site would have arrived at just about the same time as the atmospheric travel time of the ejecta. That was our big breakthrough.”

    “The seismic waves start arising within nine to 10 minutes of the impact”

    “The tektites would have come in on a ballistic trajectory from space, reaching terminal velocities of between 100 and 200 miles per hour”

    Over 1,800 miles (3,000 kilometers) away, miniscule ejecta overrides normal wind direction; especially the jet streams?

    Seismic waves? How are these documented and verified?
    Height of local land disturbance?
    Length of time for the land disturbance?
    Exactly how many seismic waves does a meteor strike 1,800 miles away cause?

    Keeping in mind that Central North America was an inland shallow sea, just how much of a tsunami is left after 1,500 miles of spreading out over the friction of a shallow sea bed?

    “The 2011 Tohoku quake in Japan, a magnitude 9.0, created six-foot-high seiches 30 minutes later in a Norwegian fjord 8,000 kilometers away.”

    Thirty minutes later?
    Norwegian fjord 8,000 kilometers away?
    Well,color me gobsmacked!
    Exactly how does a shockwave of moving water reach a Norwegian Fjord, thirty minutes later?
    Norway is the yellow pin, fjords are along the Western Coast,
    Tohoku-oki is approximately where the red pin is located.
    https://www.dropbox.com/s/zsv2ryf0wikak8k/Tohoku-oki%20toNorway.JPG?dl=0

    “The tektites would have come in on a ballistic trajectory from space, reaching terminal velocities of between 100 and 200 miles per hour”; 100 miles per hour is roughly equivalent to 8,800 feet per second (2.7 km per second).
    A speed that should bury pellets deep or vaporize them depending upon surface hit, including pine sap.

    Their description of how the globules are found is more typical of fallout after circumnavigating the world; falling from the atmosphere at reduced speeds.

    If they can prove local seismic wave land movement and amplitude, they might have a possible explanation for local tsunami.

    Gross assumptions.
    Existing Confirmation Bias, i.e. they entered into this research to ‘prove’ a forty year old postulation.
    Bad research.
    All result in questionable science and conclusions.

    • I think you are missing the point.

      They’ve got a site that documents large tektites to a flooding that mixed marine and fluvial fauna with burning wood all killed suddenly and not scavenged later. That’s the science part and is remarkable. It strongly suggests a sudden catastrophe linked to a large meteorite impact at the time of the KT.

      The speculation about how it happened exactly is licit, and even if wrong it does not detract in the least from the remarkable finding. Authors present the evidence and are allowed to speculate on how it was produced. The scientific discussion should center first on what exactly the evidence demonstrates. Discussions about speculations are unproductive.

      • ‘2.7 km per second’

        The decimal point is at least lost and found in wrong place.

        100 miles per hour is 0.044 km per second, or in local customary units, ‘almost 200 km per hour’

    • Don’t mean to be picky, but according to ‘Convertunits’, 60 mph equals 88 fps, hence 100 mph equals ~146.7 fps. Don’t know how that might change your thinking.

    • Gulf of Mexico, east Texas/ western Louisiana, turned up (muted) in tide gauges . Reports of waves crashing on Galveston seawall, sloshing of swimming pools in Houston.

      Donn, W. L. 1964. Alaskan earthquake of 27 March 1964: remote seiche stimulation. Science. 145:261-262.

    • ATheoK, considering seismic waves, the Japan-Norway linked informations is very plausible. The shockwaves were not of moving water. The shockwaves were S waves that travel inside the upper layers of the Earth. Those were the ones linked to the generation of seiches in Norway’s coast. An S wave as an average speed of 3 to 3.5 Km/s. With about 8000km of distance, 30 to 40 minutes to reach there, even considering all the anisotrophy of the traveling mean, is very plausible.

      https://www.dailymail.co.uk/sciencetech/article-2397320/Norwegian-seiches-freak-waves-linked-2011-Japan-earthquake.html

    • Terminal velocity (where air drag forces balance forces due to gravity) of spherical object falling through our atmosphere is between 100 and 200 mph ( the exact speed is dependent on the shape of the body). Skydivers can reach 125 mph. Hail stones impact the ground at such speed, and most do not explode or even break.
      The primary impact zone would have enough such energy, but I find it rather implausible that falling glass spherules thousands of miles away could ignite ground fires.

      In recorded history I do not know of any meteorite impacts that started forest fires.
      https://www.meteorite.com/meteorite-information/meteorite-facts/

      There would have to be a VERY BIG impact to cause such immediate energy.

      • There were a lot of objects larger than glass spheres falling.
        Beyond that, the sheer number of objects falling would have caused the atmosphere itself to heat up.

    • The tektites would have taken a parabolic trajectory and as a result spent most of the flight outside the atmosphere.

      A bolide 20 miles across hits the ground and there are no seismic waves??

      Re-read the article, a seiche is not a tsunami. Completely different mechanism.

      100 mph collisions vaporize things? Not in any world I’m familiar with.

      • Not quite parabolic due to air friction. We call these trajectories through the atmosphere “ballistic”, and because of our military its a very well studied field of physics.
        And, I suspect the majority of the ejecta didn’t leave the atmosphere, but it would cool none the less.

        A seiche is merely a seismic induced water wave occurring on an inland sea or lake. On the oceans we have adopted the Japanese word for it “Tsunami”. While literally a Seiche is not a Tsunami, figuratively they are equivalent.

        I grew up near Lake Michigan. Seiches were not unheard of.

        • The trajectories are in fact elliptic for debris that lands back on Earth. Debris in parabolic trajectories will go into orbit around the Sun. They may of course be “swept up” by the Earth at some later time.

          And the ejecta that did not go above the atmosphere would land quite close to Chicxulub.

          And a seiche and a tsunami are very different. A tsunami is a series of “ordinary” waves induced by a sesmic ground displacement. A seiche is a standing wave in a bounded water area.

      • I too find the idea that tektites could ignite fires to be a bit of a reach. However, all those tektites falling through the atmosphere could build up a lot of static electricity (just as raindrops do in thunderstorms) and there could well have been a lightning storm. Lightning unaccompanied by rain does set off most of the forest fires we have today.

        My 2 cents’ worth..

    • ATheoK

      Would you care to explain how to excavate a 200+ kilometer crater without causing massive earthquakes? And by the way there are massive turbidite deposits showing that the Chicxulub impact caused large-scale submarine slides over a very large area.

      100 miles per hour = 530 ft/sec = 0.045 km/sec

      “Their description of how the globules are found is more typical of fallout after circumnavigating the world; falling from the atmosphere at reduced speeds.”

      Ever heard of air resistance? And any tectites that had “circumnavigated the world” would re-enter at about 8 km/s (18,000 mph) and vaporize

      “Exactly how does a shockwave of moving water reach a Norwegian Fjord, thirty minutes later?”

      It doesn’t. The seismic shockwave moving through the solid earth does however, and seismic waves can cause quite strong seiches (=standing waves) if they happen to match a resonant frequency of a water body. For example earthquakes in northern California have been known to cause the water to slosh out of swimming pools in southern California. The Chicxulub earthquake has been calculated to be about magnitude 11 so it might quite easily have caused a strong long-period seiche in an arm of the Midwest sea. The tsunami on the other hand would probably have been quite weak by the time it reached North Dakota since tsunamis decay rapidly in shallow water.

    • “The tektites would have come in on a ballistic trajectory from space, reaching terminal velocities of between 100 and 200 miles per hour”; 100 miles per hour is roughly equivalent to 8,800 feet per second (2.7 km per second).
      A speed that should bury pellets deep or vaporize them depending upon surface hit, including pine sap.
      Your math seems off.

      • Your math is way off:

        100 miles/h = 530 foot/s = 0.045 km/s

        8800 foot/s = 2,7 km/s = 6040 miles/h

        • Dude, what kind of math are you doing?

          (100 miles/hour)*(5280 feet/mile)*(1 hour/3600 sec) = 146.7 feet/sec = 44.7 meter/sec

    • “Exactly how does a shockwave of moving water reach a Norwegian Fjord, thirty minutes later?”

      Not a shockwave of moving water but a shockwave.
      A seismic shockwave has a veocity of around 2 to 8km/second through the crust
      https://www.sms-tsunami-warning.com/pages/seismic-waves#.XKKueKZS_cM
      Assume a conservative 2km/s….that’s 7,200km/hour

      If the shockwave was travelling at a more sprightly 4km/s it would easily have reached a Norwegian fjord from Japan in 30 minutes.

    • As far as the seizmic waves are concerned, they travel through the crust as they spread out.
      This places the seizmic wave propogation speed at 8800/30/60 or 4.8k per second.
      100 mph as fps is 100*5280/60*60
      Your figure: 100*5280/60 or 8800′ is feet per minute rather than second

    • “The Day the Dinosaurs Died”- I immediately think of the Don McLean hit song.

  12. Richard and Walter Alvarez have always been a couple of my science heroes. They do science right.

  13. How much money is wasted on speculative research about the earliest years of life on earth – which is long dead and gone – which could be far better spent on research of life beneath our feet and in our seas that has barely been scratched.

    • Dude!!! – all geology research, which is part and parcel of paleontology research, is about events over, well, geological history, as in millions and billions of years.

      Its relevance to current economics is that geologists and geo-engineers, and related areas including petroleum engineering, are the ones who find all the oil and gas that powers your life and the world’s economies.

    • All knowledge is interconnected. Understanding the past increases our understanding of the present.

      Its like the question why humans have totally useless tail bones. If you didn’t know how humans evolved you would never be able to understand present day human anatomy.

      • Exactly. The threads/chains/webs of cause and effect never break. And our lack of knowledge of the past is key to understanding our lack of understanding of the present. Our ignorance of both past and present explains why we are so poor at predicting the future.

    • Ever heard the expression: “The past is the key to the present”

      It was coined by Charles Lyell, “the father of geology”, with reason.

  14. Dead fish , Chaotic death assemblage, tektite debris found in fish and in surrounding mud sounds like their explanation is the only possible one that fits the facts, with all these smoking guns Hercule Poirot would amake the same case . Maybe Atheok would care to speculate on another cause before getting snotty.

    This paper smacks of exciting science . There are others who invoke other reasons for KT extinction event . Mostly they seem able to disagree in a scholarly manner and by disagreement probably advance the cause of science by erecting falsifiable hypotheses and then testing them.
    It is refreshing to read real science in contrast to the vapid maunderings of many in the climate debate.
    No ad hominem attacks here although I do have some very tempting targets and you all out there know who they are.
    The propagation wave velocity of the Norwegian fjord sounds a bit suspicious 8000 km in 30 minutes sounds like 16000 Km/hr=4400 m/sec that is a sort of typical fast sedimentary rock Pwave velocity. Water velocity is 2400 m/sec Tsunamis seem to travel at speeds of around 4000m/sec. was the Norwegian seiche caused by an attenuated tsunami wave or some sort of earth propagated seismic wave ?

  15. Looking at Cataclysmic events in our history, I have just come across a book, The Adam and Eve Story by Chan Thomas, which the CIA had classified at some point after it’s 1963 publication only for a recent FOIA to have a sanitised copy declassified in 2013, in document form.
    The PDF file can be found in the CIA website under the Library section.
    The book relates the cyclical history of Cataclysmic earth events due to the Crustal Displacement theory, which I am sure many people here will have some thoughts on. (psuedoscience?)
    Crustal displacement of 90 deg, back and forth over time, every 6,000 to 10,000 years, or thereabouts, which the author explains and expands upon the last 2 events from historical writings, Noa’s great flood and Adam and Eve, plus from cross scientific research and archaeological anomalies.
    Ultimately he tries to find the trigger for such events.
    If anything, it gets the imagination going, especially as to why it was deemed by the CIA the necessity to classify it!

  16. Don’t forget what was done to Velikovski for his daring to suggest that Earth’s “geological and evolutionary” history might have been determined, not by “steady state”, but also very much by cataclysms attributed to periodic meteor or comet impacts. (Answer, everything but physically “hung from the yardarms”.)

  17. I guess they are assuming only one meteorite in a single rifle shot scenario without any breakup fragmentation on entry in the stratosphere.

      • That probably happened hundreds of million years earlier. However such collisions can cause very high frequencies of meteorite impacts for a while afterwards. Google “Ordovician meteor event” and “L-chondrite body”.

    • There only seems to be a single, very big, crater of that age, but that may change in the future. The Boltysh crater in Ukraine is about the same age, and it has been suggested that it might be related. There is certainly only one impact layer, so any multiple impacts would have to be very close in time.

      Multiple impacts are difficult to prove, and I think that Rieskessel + Steinheim is the only well-documented case. It has been suggested that five mid-Triassic craters might be from a single crater-chain type serial impact, but that is very uncertain:

      https://geosci.uchicago.edu/~rowley/Rowley/Publications_files/Nature%201998%20Spray.pdf

    • That’s a cool site. I really like the concept.

      However, I take exception that, while the inland sea was present in the image of North America 90 million years ago, it is not present in North Dakota on the 66 million years ago image. If the hypothesis is that waves in a shallow inland sea in present day North Dakota buried this site during the impact event approximately 66 million years ago, why isn’t that sea present in the image depicting the earth 66 million years ago?

      Very strange. Maybe I’m missing something.

  18. Tsunami vs. seiche

    There is another possibility that could reconcile the difference in time between the proposed wave that deposited the fossils and the rain of tektites. The impact would have created an earthquake. The earthquake in turn could have created a rockslide or landslide nearer to the fossil site. The rockslide or landslide could have in turn then created a tsunami like the one that happened in Lituya Bay, Alaska in 1958.

    • As a matter of fact we do know that the impact caused massive submarine slides, so that is definitely a possibility, though North Dakota was pretty flat in the Cretaceous too.

    • Phil – The authors consider other factors such as landslides in their section called ‘Emplacement Mechanism’ in the proof of the paper that is now available on-line. They seem to have solid arguments for their preferred mechanism. I put a link to the paper above in a reply to tty (I’m afraid repeating it might annoy the moderator).

  19. I’m hoping that DePalma’s interpretation is correct, but the skeptic in me will await the paper, the inevitable reviews, and the sets of fresh eyes that need to evaluate the site. DePalma has some heavy hitters on his side so I am tentatively trusting the story, but it has yet to pass both academic review and independent field study. The discovery of an essentially instantaneous snapshot (i.e. within an hour) of the K-T Chicxulub impact is an extraordinary claim and must be subject to intense scrutiny.

  20. Its all very interesting but I am puzzled that we still had life surviving.
    I would think that with modern DNA that it should be possible to trace back
    the various major groups of life to that single punt when we had the 3 %
    of life surviving, and what form was this life, and how was it that it survived..

    The birds from dinosaurs for example. Yes there were small dinosaurs but they to had to eat, so what on if it was all destroyed by fire. Was it possible that this mass extinction did not occur all over the planet ?

    MJE VK5ELL

    • “I would think that with modern DNA that it should be possible to trace back
      the various major groups of life to that single punt when we had the 3 %
      of life surviving”

      And that is exactly what we find when we study the DNA of birds. Almost all major groups differentiated in a very short time (geologically speaking) about 65 million years ago. Only a very few lines go back into the late Cretaceous. Probably very few bird species, perhaps less than 10, all belonging to a single sub-group of the very diverse Cretaceous birds (the ornithurines) survived.

      http://cdn.sci-news.com/images/enlarge/image_2340e-Avian-Family-Tree.jpg

      • Frightened birds take to flight and that probably didn’t help. Frightened rats go underground and that probably helped. Anything on the surface or the air had a slim chance of surviving. Marine critters coped a little bit better. In any case macroscopic life was nearly wiped that day and the following months. Every surviving species must have lost nearly all its individuals as survival was anecdotal. Life on Earth took many millions of years to recover, and that is an awful lot of time considering how fast life reproduces.

        • Every surviving species must have lost nearly all its individuals as survival was anecdotal.

          And that probably finished off a few more species… with survival so rare, another survivor of the same species but opposite gender could be thousands of miles away, so they couldn’t possibly live long enough to find each other. Not every survival story has a happy ending.

          • Birds would have a better chance in that respect, being more mobile. But on the other hand a single pregnant female mammal could be enough to perpetuate a species while this is less likely for birds.

    • And no, the mass extinction occurred everywhere. But there are some hints that it may have been slightly less severe in and around Antarctica. Several of the surviving groups seem to come from there.

    • An excellent suggestion, Steven! We should set up a GoFundMe account to support this.

      When would you be available to be hit with a 30 foot wave, pelted with 100 mph/5 millimeter diameter glass balls for 10 – 20 minutes, and then entombed in sand and silt by a second wave for the next 66 million years?
      };>)

    • Just wait, it will happen.

      Fortunately not very soon on that scale. It is extremely unlikely that any 10-km earth-crossing asteroid hasn’t been found and had its orbit calculated by now, but a smaller one could impact tomorrow.

      And of course there is always the chance of some new comet coming in from the Oort cloud and scoring a direct hit. The warning time would only be a few months in that case. At best.

  21. This is a fascinating paper! From a fascinating find! A 30-minute slice of time captured and preserved from 66-million years ago, well the odds against that happening might be even higher than the odds against the creation of life itself (if it had to rely solely on chance alone)! The author’s interpretation of the data may be all wrong, but he’s (they’re?) putting it out there where everyone can see it and argue about I mean discuss it (I can understand concerns about vandalism and/or sabotage, and data integrity, but they’ll have to allow other researchers access to the actual site itself sooner rather than later), but just the sheer volume of data, that many species represented, the mud funnels for the larger tektites (there’s a research field all by itself… they can get the grain size from the rock, but what masses, what velocity, what temperature, what moisture content, does it take to get mud to behave like that?), even the presence of the triceratops, an amazing wealth of data. This is the way science should be done!

  22. Here is a recent YouTube which is well narrated that discusses the recent stusy showing that the impact carter in southern Chile dates to arouns 12,800 years ago. Thus leading to the conclusion that it was this impact along with other fragments striking elsehwere around the lanet which caused the YD, …

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