Two mountain peaks in China - Front Baijifeng and Rear Baijifeng - were found to have essentially been created by the impact of a meteorite which fell from the sky hundreds of millions of years ago, making it the first confirmed mountaintop crater.
Researchers at the Center for High Pressure Science and Technology Advanced Research in Shanghai “set out to find” the origin story of rocks known as “celestial stones” at the Baijifeng Mountain, located in northeastern China, not far from the North Korean border.
“We set out to find out the real story behind this accumulation of rock fragments”, the team, led by researchers Ming Chen and Ho-Kwang Mao, wrote. “Our investigation has revealed for the first time the presence of an impact structure on Baijifeng Mountain.”
After examining the rock fragments they found their make-up to consist of sandstone and granite, both of which contain small quartz minerals. The authors then found specific deformations usually caused by heat and pressure.
The deformations are “widely accepted as diagnostic evidence for shock metamorphism and terrestrial impact structures,” the authors write. As such, it indicates they came from a meteorite impact site which spans about 4,600 feet (1,400 meters) and formed the two peaks known as Front Baijifeng and Rear Baijifeng.
“During the impact cratering,” the researchers write, “a large amount of rock would have been excavated and ejected to form this new geological structure. The collision would have greatly changed the original terrain of the target, forming two new peaks, namely, Front Baijifeng and Rear Baijifeng.”
The researchers are unsure of when the crater was actually formed, but believe the meteorite could have hit the mountain after the Jurassic Period—between 150 million and 172 million years ago. But in any case, they will have to do further tests to confirm whether a meteorite really was responsible for changing the shape of the mountain.