Robert sent in a link to an article that claims volcanoes did not cause the extinction of the dinosaurs – a counter view to the 'asteroids what did it' meme. Asteroid strikes are still disliked by uniformitarians. Robert's link is https://phys.org/news/2021-09-extreme-volcanism-massive-extinction-speci… … with the comment, oh yes they did, oh no they didn't. An argument that goes back and forth, to and fro. The new paper involves foraminifera fossils used as a biostratigraphic indicator in the Zumaia sediment of the Basque country ![]()
. The conclusion is that these are marls [a form of clay] and limestone [presumably chalk, which is thick with coccoliths, or broken algal shells]. There is said to be rhythm about the laying down of these stripey layers. The manner of the sedimentation is said to reveal cyclical variations in the earth's axis as well as its orbital movement around the Sun. The Milankovitch cycle. I've heard this sort of thing before and it involves dating each stripey layer by uniformitarian means as a certain passage of time multiplied by the number of stripes, or waves [depending who is selling the story]. We are talking about a big asteroid strike that must have instantly created sediment beds. It is just as likely the marl and chalk was laid down by water fairly quickly. We even have an article on just this sort of scenario coming up later in the weekend. Marl, as it exists beneath chalk in the UK, is usually a mix of chalk and clay. The formation isn't really as distinct as required by the authors. What the authors have done is use a uniformitarian explanation of the Zamaia formation to refute the idea that massive volcanism, such as the Deccan Traps, occurred later than the impact and may have been the real cause of the dinosaur extinction. However, the authors also want to blame the asteroid for the demise of the dinosaurs, a catastrophist event. It is somewhat amusing they have used uniformitarianism to counter a uniformitarian argument.
The paper also mentions an algal bloom in the aftermath of the impact event [or is it prior as it gets confusing]. Funnily enough, this week we also had a paper that claimed Australian wild fires a couple of years ago caused an algal bloom in the Southern Ocean. One might therefore make a connection between algal blooms at the K/Pg boundary and wildfires that occurred as a result of the asteroid burning up as it passed through the atmosphere, and the energy within the impact itself. In uniformitarian geology the chalk comes before the impact. I wonder.
The link to the wild fire article is https://phys.org/news/2021-09-australian-wildfires-triggered-massive-alg…
