Cretaceous-Tertiary Extinction Event

The Cretaceous-Tertiary Extinction is probably the one you’ve heard about, the one that killed off the dinosaurs. In addition, more than half of all Earth’s species became extinct. Two theories of causation have come to the forefront: asteroids and volcanoes. Asteroids seems a bit cooler and stems from the finding of a rock, dated to be at the time of the extinction event. This rock was rich with iridium, which is found in asteroids. To further support this claim, a crater in Mexico’s Yucatan Peninsula measures to be 110 mile wide. On the other hand, iridium is found in the earth’s core and could have crept to the surface through volcanoes. The soot from the massive volcano eruption may have blocked the sun, causing immense environmental change. Both have merit and some even suggest that both theories could have had a hand in causing this massive event.