Did a Chicxulub impact wipe out dinosaurs?
If not, what did?
First published 10 April 2021, last updated 20 April 2023
Mr R.R. from Wisconsin asks about a topic that has baffled both creationists and evolutionists for about 200 years: the extinction of the dinosaurs. The common evolutionary view of a meteorite impact was once considered outlandish, but now it’s considered outlandish to doubt it.
The biblical creationist view must involve the global Flood of Noah’s day. Because dinosaurs were land vertebrates, two of every kind must have been passengers. So why are they extinct now?
I saw some old articles regarding meteor impacts. It seems like there have been new developments by the secular scientific community though. The Chicxulub crater is now touted as the source for dinosaur extinction and that the event potentially only had to last for a few decades. There’s also mention of a layer of asteroid dust that exists around the entire world. I’m wondering if you have an explanation for the Chicxulub crater and also for the layer of asteroid dust that some scientists claim exists around the globe.
Dear Mr R.
Thank you for writing to CMI.
The extinction of dinosaurs has been a mystery for both the creationists and evolutionists ever since they were (re-)discovered in the 19th century. There are over 100 theories for why the dinosaurs went extinct. Some of these include theories such as the idea that dinosaurs died out due to carbon dioxide accumulation from volcanic eruptions, global warming/cooling, epidemics, or from predation by egg-eating mammals. More novel ideas include extinction from newly evolved narcotic plants, chronic constipation, and shrinking brains. The fact that there are so many different theories suggests to us that secular researchers do not really have a good solution to the question.
This Chicxulub impact idea is all the rage now, but even evolutionists point out problems. The impactor was either a stony asteroid or a comet, diameter 10.6–80.9 km, mass 1.0×1015 kg to 4.6×1017 kg, and energy 1.3×1024 J to 5.8×1025 J.1 To put this into perspective, the most powerful nuclear weapon ever exploded, the Soviet RDS-220 hydrogen bomb or ‘Tsar Bomba‘, produced 2.10×1017 J. So, even the lowest estimate of the Chicxulub explosion means the equivalent of over 6 million Tsar Bombas.
In the theory, the impactor threw 60 times its mass in pulverised rock into the stratosphere. The resulting dust blocked out the sun causing a global cooling effect that wiped out 50% of all life, including the dinosaurs.
The support for the idea stems from thin iridium layers that exhibit characteristics consistent with a huge meteoroid strike. These thin layers are generally thought to be found in rock layers all around the world at the K-Pg (formerly K-T) boundary—the supposed time of dinosaur extinction according to evolutionists.
However, this iridium layer is not as well-defined as previously once thought. There are currently over 100 known iridium anomalies. There is much circular reasoning about the K-Pg boundary. That is, dinosaurs died out at the K-Pg boundary. How is this defined? Simple: any rock layer with dinosaur remains or tracks proves that it’s below the boundary.2
Ironically, there is hardly any iridium in the site of the ‘smoking gun’ itself, or in the ejecta claimed to be directly caused by this gun.3
We don’t rule out meteorites at the time of the Flood, because they are consistent with the biblical Flood model, which speaks of the windows of the heavens being opened (Genesis 7:11, 8:2). So, it would not be surprising to find traces of such an impact in the Flood layers.
All secular theories for the extinction of dinosaurs face numerous problems, including the Chicxulub theory. For example, if an asteroid hit the earth leading to a nuclear winter, how did the photosynthesis-dependent plants survive? Why did delicate bees and moths, or even sensitive amphibians such as frogs and salamanders survive? If volcanic activity and toxic gases filled the earth after an extinction event (such as with the volcanic or carbon dioxide theory of extinction), then why did the birds survive? Birds have a unique and very efficient lung design, but that makes them more vulnerable to toxic gases (cf. canaries in coal mines).
Bible-consistent extinction theories
Some creationists have sometimes pointed to the fact that since dinosaurs lived at the same time as man after the Flood, hunting could have contributed to its extinction. Many animals around the world have gone extinct due to hunting.
Similarly, several ancient legends speak of heroes slaying dragons. These ‘dragons’ may have been dinosaurs. There is much archaeological evidence that suggests that people a few millennia ago were familiar with dinosaur-like creatures, so possibly these creatures were hunted to extinction. Could hunting have killed off all the dinosaurs? Hunting might have played a part in the extinction of big and dangerous dinosaurs, but it is hard to see how hunting would have killed off the smaller dinosaurs deep in the unexplored jungles.
Most biblical creationists believe that there was a single ice age event that started a few hundred years after the Flood and peaked around 500 years. The cold weather might have made it difficult for post-Flood dinosaurs to survive in the polar regions, but the ice age does not explain why dinosaurs went extinct at the equatorial regions. Nor would it explain why the dinosaurs went extinct, but not many other reptiles like the crocodilians or large snakes. But this is also a problem for the evolutionists who appeal to global cooling or a nuclear winter following the supposed asteroid impact.
The extinction of dinosaurs may be the result of a combination of different factors: climate, human hunting, inability to adapt to the post-Flood world, the loss of suitable food, lack of genetic diversity, habitat, etc. The same is true of other extinct creatures.
Update, 20 Apr 2023: A new study led by Dr Lauren O’Connor, a paleoclimatologist at Utrecht University in the Netherlands, has questioned whether prolonged global cooling or ‘nuclear winter’ would have resulted from a Chicxulub impact. Nor would any warming, for that matter. A study analyzed fatty compounds in fossil peat from Saskatchewan, Canada, to derive mean annual air temperature (MAAT) through the uniformitarian K–Pg boundary. The analysis spanned the last 4,000 (uniformitarian) years of the Cretaceous and the first 30,000 years of the Paleogene. In fact, MAAT peaked in the first millennium of the Paleogene. Any cooling was quite mild and gradual: MAAT cooled from an average of 25°C to 20° in the first 30,000 years after the impact. “Further, no long-term impact- or volcanism-driven warming is evident.”4,5
Mike Oard had previously proposed, “The Chicxulub impact may have caused global temperatures to drop greater than 26°C for 3–15 years, with residual effects lasting up to 30 years.”6 This doesn’t fit uniformitarian models, but matches very well with creationist models of a single Ice Age caused by the Genesis Flood.
Instead, Dr Sean Gulick, a geophysicist at the University of Texas at Austin, suggested that the atmospheric dust caused global darkness lasting a decade at most (‘nuclear night’?).7 In 2021, some geologists proposed that such darkness would have killed most plants, the base of the food chains and webs, in under a year.8 I.e. with no plants, herbivores have nothing to eat, then carnivores would have nothing to hunt. But to uniformitarians, a year or a decade is regarded as an undetectable ‘blip’ on the geological timescale.
However, the problems raised above for the nuclear winter seem even more acute for the nuclear night theory. We know that many photosynthetic plants survived the supposed impact, as did many delicate creatures that depend on them.
References and notes
- Durand-Manterola, H.J. and Cordero-Tercero, G., Assessments of the energy, mass and size of the Chicxulub Impactor, arXiv:1403.6391v1, 19 Mar 2014. Return to text.
- Oard, M., End-Mesozoic extinction of dinosaurs partly based on circular reasoning, J. Creation 15(2):6–7, 2001; creation.com/dino-extinction. Return to text.
- Clarey, T., Chicxulub crater theory mostly smoke, Acts and Facts (ICR), 31 May 2017. Return to text.
- O’Connor, L.K. and 9 others, Steady decline in mean annual air temperatures in the first 30 k.y. after the Cretaceous-Paleogene boundary, Geology, 22 Mar 2023 | doi:10.1130/G50588.1. Return to text.
- Thompson, J., Dinosaur-killing asteroid did not trigger a long ‘nuclear winter’ after all, livescience.com, 19 Apr 2023. Return to text.
- Oard, M., Flood impacts reinforce volcanic cooling to start the Ice Age, J. Creation 33(1):77–84, 2019; creation.com/flood-impacts-cooling. Return to text.
- Gulick S.; cited in Thompson, Ref. 4. Return to text.
- Weisberger, M., Darkness caused by dino-killing asteroid snuffed out life on Earth in 9 months, livescience.com, 22 Dec 2021. Return to text.