Webosaurs Blog

The white layer is rich with iridium at the Cretaceous/Tertiary (K/T) boundary

Q: Isnt there like a huge lime deposit all over the earth around the time they said the meteor hit? -Morty

A: I’m so glad you asked this question, Morty. I think what you are referring to is the iridium layer that occurs at the K/T boundary. Confused yet? The rock formations you see in the mountains and on the earth are like looking back into history. Different layers and formations were created different eras and periods of time. Studying these layers and how they interact can tell us a lot about the ancient history of our world.

Dinosaurs died out at the end of the Cretaceous period and life began to rebuild during the following period, the Tertiary (or most accurately the Paleogene). There is something interesting that occurs where Cretaceous rock formations meet Tertiary rock formations. Scientists have found a layer that is very rich in iridium, a metallic element that is very uncommon in the earth’s crust. It is normally so rare that scientists can’t even measure it using scientific instruments.

At the K/T boundary, though, there is enough iridium to measure and the element is found widely distributed throughout the world at this geologic time boundary. This is interesting because iridium is a lot more common in meteorites, comets and asteroids. This is one of the many reasons that a lot of scientists think that an object from space killed off the dinosaurs.

Wow, that was some intense reading. Feel free to ask any questions about this if you have them. If not, shoot me a question for what I should answer tomorrow!

-Rex

Tags: Daily Dino Fact, Dinosaurs, geology, iridium layer, webosaurs