World's first mountaintop impact crater found in NE China

BEIJING, Sept. 9 (Xinhua) -- Chinese scientists have discovered the world's first-known mountaintop impact crater in the country's northeastern region, according to the Center for High Pressure Science &Technology Advanced Research (HPSTAR) in Beijing.

With a diameter of 1,400 meters, the impact crater is located on the top of Baijifeng Mountain in the Baijifeng National Forest Park in Tonghua, Jilin Province. It is a cirque-shaped depression, with a height difference of about 400 meters from the highest rim to the lowest rim, said Chen Ming, a researcher at the HPSTAR.

Scientists believe it was formed by a bolide impact, which took place after the Jurassic Period. It explains the distribution of a large number of rock fragments composed mainly of sandstone, with a small amount of granite, on the top of Baijifeng Mountain as they were ejected from the impact crater during the impact event.

The formation of the impact crater also changed the original topography of Baijifeng Mountain, reforming its top into a double peak with elevations of 1,318 meters and 1,300 meters.

"Most asteroids impact Earth's surface, creating bowl-shaped craters or complex craters with center peaks," said Chen, adding that the discovery thus provides a new perspective for exploring the mechanisms of impact crater formation and the shock-metamorphic effects in unique terrains and landscapes.