Scientists have confirmed that a circular mountain ridge in China’s Heilongjiang Province is a crater made by an asteroid strike. The study published in the journal Meteoritics & Planetary Science. Scientists described their study of the crater and what they learned about it.
Scientists noticed what looked like a crater in the mountains of northeast China. Scientists looked at newer satellite images of the site and grew more convinced that it was a crater. Scientists then made arrangements to study the crater up close. Scientists extracted a drill core from its center, in addition to surveying the crater and the area around it.
Study of the core showed that the crater bottom was made of lacustrine sediments from an ancient lake which later became a swamp. Underneath was a 319-meter-thick layer of brecciated granite along with granite clasts and fragments. Evidence of shattered bedrock due to a very powerful collision. They found melt products such as vesicular glass and teardrop-shaped glass. Both of which would have needed high temperatures to form as they melted and then cooled in situ.
Scientists also found deformation features in other local quartz. They taken together the core’s features provided strong evidence of an asteroid impact. Scientists also found the crater was approximately 1.85 kilometers wide. Though its southern rim has worn away leaving the crater in a crescent shape.
They found that the rim was approximately 152 meters tall at its tallest point. Radiocarbon dating of charcoal in the area and old lake sediment showed the crater was formed approximately 46,000 to 53,000 years ago. This time suggests the impact could have been witnessed by early modern humans or other relatives living in the area. They were unable to determine the size of the asteroid that made the crater but suggest further work may help to form estimates.