Scientists revealed in their findings how crater impacts created rings of mountains and peaks in just ten minutes.
Not all mountain rings or peak rings were created from massive crater impacts. Most of these formations were tectonic in origin which could take millions of years to form. Peak rings of impact craters are commonly found on the surface of our neighboring planetary bodies like the moon and Mercury.
The most distinct peak rings formed through crater impacts here on earth is in Chicxulub crater in Yucatan Peninsula, Mexico. The portion of the peninsula was hit by an asteroid or meteor around 66 million years ago. The crater was 200 km wide diameter and 20 km deep. Chicxulub impact was also linked to the massacre of dinosaurs.
Researchers, at first were not sure how they were formed. They came up with a couple of explanations. One proposed explanation was these mountains were formed from a spike of deep rocks to the surface due to the impact. Another suggested that rocks were assembled in an area around the crater.
Rocks extracted from the site of impact confirmed the first explanation. It also confirmed that the crater's peak rings were made from deep rocks.
Computer generated gravity map image of the Chixulub Crater
Sean Gulick, a geophysicist at the University of Texas at Austin and his team went on a drilling expedition off the coast of Mexico and on the surface above Chicxulub peak rings. Rock samples extracted from 750 to 1,300 meters deep contained pieces of granite and minerals. These materials are normally found deeper than where they were extracted. The rocks would've been resting deeper within the crust before the impact. That meant the rocks found in the peak rings might have been churned out on to the surface., the same way how water spurts out onto the surface when a rock is dropped.
The deep rocks became more porous than they should've been deeper on earth. It was found that deep rocks in the region averages 2.6 grams per cubic centimeter. The peak rings rock averages 2.41 grams per cubic centimeter. They are also found to be heavily fractured.
Ross Potter, a planetary scientist at Brown University added that the porous rocks of impact rings could also explain the porous rocks on the surface of the moon.
“You may be able to find very interesting samples that tell you a lot about not only the cratering process itself, but also the interior of the planet and how the planet formed.”
The researchers report is published in Science