It Really Was the Asteroid That Ended the Dinosaurs – Here’s How It Went Down

Impact and Aftermath Preserved in Stone

The picture shows the Cretaceous-Palaeogene boundary at Geulhemmerberg in the Netherlands, where the boundary clay samples were taken. The event bed is clearly visible as a grey clay-rich layer, between the otherwise yellowish carbonate sediments. It was thought to have been laid down during calm periods between strong storm events. Credit: Michael Henehan

Fossil remains of tiny calcareous algae not only provide information about the end of the dinosaurs, but also show how the oceans recovered after the fatal asteroid impact. Experts agree that a collision with an asteroid caused a mass extinction on our planet, but there were hypotheses that ecosystems were already under pressure from increasing volcanism. “Our data speak against a gradual deterioration in environmental conditions 66 million years ago,” says Michael Henehan of the GFZ German Research Centre for Geosciences. Together with colleagues from the University of Yale, he published a study on October 21, 2019, in the scientific journal Proceedings of the National Academy of Sciences (PNAS) that describes ocean acidification during this period.

He investigated isotopes of the element boron in the calcareous shells of plankton (foraminifera). According to the findings, there was a sudden impact that led to massive ocean acidification. It took millions of years for the oceans to recover from this acidification. “Before the impact event, we could not detect any increasing acidification of the oceans,” says Henehan.

The impact of a celestial body left traces: the “Chicxulub crater” in the Gulf of Mexico and tiny amounts of iridium in sediments. Up to 75 percent of all animal species went extinct at the time. The impact marks the boundary of two geological eras – the Cretaceous and the Palaeogene (formerly known as the Cretaceous-Tertiary boundary).

Henehan and his team at Yale University reconstructed the environmental conditions in the oceans using fossils from deep-sea drill cores and from rocks formed at that time. According to this, after the impact, the oceans became so acidic due to the rainout of sulphuric acid from the vaporized crater rocks that organisms that made their shells from calcium carbonate could not survive. Because of this, as life forms in the upper layers of the oceans became extinct, carbon uptake by photosynthesis in the oceans was reduced by half. This state lasted several tens of thousands of years before calcareous algae spread again. However, it took several million years until the fauna and flora had recovered and the carbon cycle had reached a new equilibrium.

The researchers found decisive data for this during an excursion to the Netherlands, where a particularly thick layer of rock from the Cretaceous-Palaeogene boundary is preserved in a cave. “In this cave, an especially thick layer of clay from the immediate aftermath of the impact accumulated, which is really quite rare” says Henehan. In most settings, sediment accumulates so slowly that a rapid event such as an asteroid impact is hard to resolve in the rock record. “Because so much sediment was laid down there at once, it meant we could extract enough fossils to analyse, and we were able to capture the transition,” says Henehan.

Most of the work was done at his former place of work, Yale University. Now, at the GFZ, he is using the infrastructure here and hopes that this will provide a major impetus for his work. “With the femtosecond laser in the HELGES laboratory, we are working to be able to measure these kinds of signals from much smaller amounts of sample,” says Henehan. “This will in the future enable us to reconstruct disturbances in the Earth-climate system at really high resolution in time, even from locations with very low sedimentation rates.”

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Funding: The main part of the study was done at Yale University, with financial support from the Yale Peabody Museum.

Reference: “Rapid ocean acidification and protracted Earth system recovery followed the end-Cretaceous Chicxulub impact” by Michael J. Henehan, Andy Ridgwell, Ellen Thomas, Shuang Zhang, Laia Alegret, Daniela N. Schmidt, James W. B. Rae, James D. Witts, Neil H. Landman, Sarah E. Greene, Brian T. Huber, James R. Super, Noah J. Planavsky and Pincelli M. Hull, 21 October 2019, PNAS.
DOI: 10.1073/pnas.1905989116

25 Comments on "It Really Was the Asteroid That Ended the Dinosaurs – Here’s How It Went Down"

  1. Please don’t write articles if you can’t put together a sentence, use proper punctuation and grammar, and flat out just can’t speak English apparently. Your article is flawed and filled with data that isn’t accurate or tested, and if you were unfamiliar with the topic, you would have no idea what you were talking about.

    • Appears to be a grammatically correct article written in lucid prose that is easy to follow regardless of ones familiarity with the subject. Guy, if you’re trying to deny the fundamental process of sedimentation, the existence of fossils, or our ability to measure and interpret changes in the chemical composition of the oceans through time you might want to go back and finish high school before you post such comment here.

  2. The wisdom of man is but foolishness to God!

  3. Ken from Philly | October 22, 2019 at 2:25 pm | Reply

    Wow David, I studied that in Bible Study last night, so true!

  4. Lol @ these commenters.

  5. People make up lies and reject truth. Evolution thinking is NOT scientific. Big bang theory defies laws of thermodynamics. Any honest and rational person knows better than these headlines state.

  6. I love this Artie. It really hits the nail on the head.

  7. @Guy, autocorrect, am I right fellas?

  8. I can hardly wait to see who among you will have the last laugh…

  9. Some of you Neanderthals, (God squad), need to watch “Inherit the Wind “.

  10. A better explanation would be the scientifically proven world wide flood of Noah’s day where only eight people survived.

  11. In “Inherit The Wind” unfortunately creationist were not represented well. There are now many, many smart scientists that have debunked the myth of evolution.

    • Evolution is one of the most verifiable scientific principles in science. The idea that there’s any debate or controversy is the actual myth.

  12. No it wasnt an astroid what it really really really was the flood save the chubby unicorn the rhino

  13. One real question should be addressed is, how can we find fossil of animals leaving at that time almost intact?
    The answer could be that those animals were buried in a very short time. So it seams logical and self explanatory.

  14. and the penguins just walked to the ark. if your god is so great, why create flawed human beings just to drown them? seems like a sadist who likes to play elaborate games.

  15. and this is why there are fossils all around the earth ? even fish eating other fish fossils? what are the odds that this little planet out in the ocean of space billion and billion of light years from us and we have a history that Jesus walked this earth, archeology proving what the bible says is true? the cities the towns the villages being found by where the bible says they are? what are the odds?

  16. he created man in his likeness for fellowship, man sinned and spread to all bringing disease and death with it , we are flawed because of sin of disobedience now that sin is in all mankind God in his love for us sent his only begotten son to die for your sins , repent of your sins and live otherwise die in your sins and face God on judgment day as to why you refused his gift of grace Jesus!

  17. Hey Guy, you should check your gooder English before belittling others for thier English…:-)

  18. The wisdom of man means everything to God.

  19. There is no conflict between The bible and the theory of evolution only the timescale. Whos to say that wasnt misinterpreted. Also its theorized that either 1 an asteroid hit the ocean or a large ice shelf broke off the Arctic causing a mass flood and Noah was warned ahead of time.. People like to say the bible is a fairy tale…just stories…well folks in those days no one just sat around scribing stories for the hell of it. It was purposeful.

  20. If any of the creationists here want to try the “just a theory” argument, you’d best start floating away. Gravity is also only a theory.

  21. What happened millions of years ago is too complex for human to comprehend or explain. The fact that there are billions of planetary bodies in the space and our earth is just like a grain of sound in their mist is testament to the fact that there are far more intelligence lives out there but we are not technologically advanced enough to reach out to those lives who could see us as rivals and exterminate us or accommodate us. I will say there really is a top supernatural power that have been existing and controlling everything and that is God.

  22. I don’t believe that asteroid smashing the earth cased the dinosaurs to go extinct.
    My theory was there was changes is ecological systems. The temperature plummeted causes frigid weather that destroyed the cold blooded dinosaurs.

  23. Steven Hawkings said it correctly…i believe there is no God. Evaluation only goes so far for so many spices. We are slaves on this planet. Here to suck this planet dry of it precious metals. Put here by another life form. Bible…true or false is a book that has been altered so badly that none of it is believable. Old Testament…new testament which version are we talking about? Brigham Youngs?? Maybe the Quaron?? My spelling is probably off but u all get what I’m saying

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