Largest Modern Impact Crater Discovered in southern China
Scientists have identified the largest known modern meteorite impact crater on earth, located within the forested hills of Guangdong Province, southern China. Named the Jinlin crater, the revelation promises to offer valuable insights into the frequency and nature of extraterrestrial impacts on our planet.
the crater, situated near Zhaoqing City, measures between 820 and 900 meters (2,690 to 2,952 feet) in diameter and reaches a depth of 90 meters (295 feet). This significantly exceeds the size of the previously recognized largest modern impact structure, the 300-meter (984-feet) Macha crater in Russia.
Researchers determined the impact occurred within the Holocene epoch, beginning approximately 11,700 years ago at the end of the last Ice Age, classifying it as a “modern” event. Evidence of a high-energy impact is clear in the presence of quartz grains exhibiting planar deformation features – microscopic markings created only by the intense shockwaves generated by celestial body impacts.
“On Earth, the formation of planar deformation features in quartz is only from the intense shockwaves generated by celestial body impacts, and its formation pressure ranges from 10 to 35 gigapascals, which is a shock effect that cannot be produced by any geological process of Earth itself,” explained Ming Chen, lead study author from the Center for High Pressure Science and Technology advanced Research.
Despite the region’s humid climate and frequent monsoons, the crater is remarkably well-preserved. The crater rim consists primarily of weathered granite soil and some granite fragments. The team is currently working to determine whether the impactor was an iron or stony meteorite.
The discovery is significant as geological processes, erosion, and planetary activity have obscured evidence of many ancient impacts. As Chen stated, “This discovery shows that the scale of impacts of small extraterrestrial objects on the Earth in the holocene is far greater than previously recorded.”
Chen further emphasized the crater’s importance as a past record,stating,”The impact crater is a true record of earth’s impact history. The discovery of the Earth impact crater can provide us with a more objective basis for understanding the distribution, geological evolution, and impact history and regulation of small extraterrestrial bodies.”
The findings are detailed in a new study published in the journal Matter and Radiation at extremes.
