Extinction-causing asteroid’s destruction dug deep to make mountains
Most mountains are created over the course of millions of years. A good jolt from a shift in the Earth’s tectonic plates may accelerate things here and there, but it’s a gradual process for the most part. To really speed things up, things need to get a little weird. Like, “the Earth’s crust temporarily behaving like a liquid” weird.
The five-minute-mountains in question can be found at the Chicxulub crater, near the Yucatan Peninsula. The crater actually has two sets of mountains, one along the outer perimeter, and an inner ring closer to the point where a six-mile-long asteroid hit the Earth 66 million years ago (destroying most living things on the planet.) The two rings of mountains weren’t unique, but only recently have scientists been able to confirm exactly how a rock hurtling into the ground could make these new geological features in so little time.
One hypothesis was that the asteroid hit and pushed a lot of rock, debris and energy outwards, basically shoving mass from the crater’s center and having it build up in two concentric circles. However, recent samples of rock drilled from deep within the Chicxulub crater found that this event was defined by vertical rather than lateral movement. Granite from six miles under the Earth’s crust was found much closer to the surface than normal, meaning the asteroid hit hard enough to penetrate the ground and shove this granite out and up into the air. The mountains then were the result of this material being displaced by around 18 miles, then settling in a ring. Researchers compared it to a water droplet causing a small splash, except that instead of actual liquids, the rock and dirt was shattered so severely that it could behave like a liquid.
An upside of annihilation
As violent as all this sounds, and as bad as it was for 75 percent of the species that went extinct afterwards, researchers also found a bit of a silver lining to such an impact. As the shattered rock fell back into it’s new, ringed configuration, it wasn’t as tightly arranged as before. The rock and debris came to rest with many fissures and cracks, all of which would have been very helpful for microbes later moving into the area. As water rushed back into the area, the porous material would have meant many minerals and nutrients would become accessible to new chemical and biological interactions. This probably didn’t matter much to most surviving species 66 million years ago, but similarly violent events with asteroids or comets further in the Earth’s past may have helped get life moving in the first place.
Source: Scientists Say Dinosaur-Killing Asteroid Made Earth's Surface Act Like Liquid by Merrit Kennedy, The Two-Way