The day the dinosaurs fell: All about K-Pg Boundary and asteroid that caused mass extinction

Around 66 million years ago, an asteroid event took place on Earth, which resulted in the mass extinction of several species of plants and animals. Not to be dramatic, but it was the mass extinction of about three quarters of the planet’s flora and fauna species. How’s that for a significant event?

The Cretaceous-Paleogene (K-Pg) boundary, also known as the Cretaceous-Tertiary (K-T) boundary, marks a significant geological transition between the Cretaceous and Paleogene periods, that took place around 66 million years ago.


This mass extinction event, when occurred, wiped out the non-avian dinosaurs and many other species. Of course, some died instantly due to the effects of the impact. But some died due to the aftermath, events like shockwaves, wildfires, lack of food source and more. Overall, it took several thousands of years for the dinosaurs to go extinct after the asteroid impact.


The evidence of this event, this whole mass extinction, was found trapped in iridium-rich thin strips of clay in rocks, in several places on the planet. In Geulhem, Netherlands, the K-Pg boundary, as it is called, is well-preserved and provides valuable insights into this pivotal moment in Earth's history.



Geulhem is situated in the southern part of the Netherlands, and the site where this piece of evidence of Earth’s history was discovered, has been well-preserved. The sedimentary rock layers that are found here span the K-Pg boundary. In simpler terms, one can lay a finger on an entire episode of a geologic event.


There, in that little sliver of clay, lies clues about the environmental changes and biological events that occurred during this time. In that line of clay lies buried evidence of what happened 66 million years ago.

But are we sure about the asteroid event?

The clay shows abnormally high concentration of the element iridium. Iridium is relatively rare in Earth's crust but is more abundant in certain extraterrestrial materials such as asteroids or comets, something from outer space. It is because of this iridium, researchers have zoned in on this asteroid impact.

Also read: Dinosaur fossils discovered In Jaisalmer is the oldest of its kind in the world


The Geulhem K-Pg boundary provides a crucial window into a momentous period of Earth's history, shedding light on mass extinctions, evolutionary recovery, and geological processes. Researchers continue to study this site and others around the world to better their understanding of the events surrounding the K-Pg boundary and the subsequent reshaping of the planet's ecosystems and life forms.