After impacting the planet’s surface for hundreds of millions of years, dinosaur diversity came to an impressive conclusion about 66 million years ago at the hot end of asteroid impact by what is today Mexico’s Yucatan peninsula.
It’s a theory that is so overwhelmed with data that it’s hard to imagine anywhere that this actually happened. If it was a cold case, it would have been rubber stamped and filed under ‘Solution’ by this time.
But scientists are a nitpicky source, and there is a tiny gap in the evidence series that links signs of a global apocalypse with the crime scene has begged for closure.
An international team of researchers collaborating on a study of material from the famous Chicxulub impact pit at the Yucatan Peninsula has matched the chemical signature of meteoritic dust inside its rock with the geological boundary representing a dinosaur extinction event.
It seems to be a clear indication that the thin blanket of dust deposited on the Earth’s crust 66 million years ago came from an impact event at this very place.
“We are now at the stage of a coincidence that will not happen geologically for no reason,” said geologist Sean Gulick of the University of Texas at the USA.
Together with fellow geoscientist Joanna Morgan from Imperial College London, Gulick led a trip in 2016 to retrieve a sample of broken rock from more than half a kilometer to the top ring of the crater.
The sample was measured by four different laboratories. Not only do the results help integrate a major transition in the fossil record with the site, they also advertise at a timeline that supports a rapid reduction in dinosaur numbers over as little as a decade or two.
“If you are really going to set a clock that went extinct 66 million years ago, you could argue that it happened within forty years, and that is basically what as long as it takes for everything to die of hunger, “Gulick said.
Fifty years ago, the question of why the diversity of fossils representing the Mesozoic era ended so abruptly in the geological record. Whatever was responsible for the sudden loss of 75 percent of life on Earth, it had to be very quick, and global.
Perceptions of such cataclysmic violence were largely based on two capacities – one emerging underground as an increase in volcanic activity, the other from above in the form of a comet or asteroid strike. world weather.
In 1980, American physicist Luis Alvarez and his son, a geologist named Walter, published a study of a thin layer of sediment that separated the Cretaceous period with a dinosaur population from the post-dinosaur world. Palaeogene.
A distinctive feature of this thin millimeter strip to a centimeter thick of sedimentary rock is an unusually high size of the element iridium, a metal not found abundantly in the Earth’s crust.
One place you can find plenty of iridium is in meteorites. So the discovery of Alvarez and his son marked the first piece of solid evidence that something exploded from space what was left across the planet at the time dinosaur biodiversity took a dive.
Surprisingly, the site of that colossal crash was the center of ongoing research around the same time, although it made a clear link between the 180- to 200-kilometer-long (112- to 125-mile) separation. ) at the southern edge of the Gulf. Mexico did not encounter the deadly asteroid until the 1990s.
Since then, evidence supporting the asteroid effect has only become stronger, with models going so far as to suggest the angle, as well as where the Chicxulub effect is, has been true. significant in the magnitude of the extinct event.
Indications that a zone of intense geological activity in western India known as Deccan Traps was emitting large amounts of greenhouse gases at the time meant that the concept of a volcano had not been emitted. completely, at least as a possible cause.
There is debate as to whether this tectonic site played any part in the famous extinct event, or even helped biodiversity overcome it.
What is no longer a real debate is whether the only rock 12 kilometers wide off the coast of present-day Mexico about 66 million years ago is the only one that removed the remains of countless dinosaurs.
“The circle is now finally ready,” said study leader Steven Goderis, a geologist from the Vrije Universiteit Brussel in Belgium.
Case closed.
This research was published in Advances in science.