Jinlin Crater: China Unveils Earth's Largest Holocene Impact Structure

Historic Discovery in Guangdong Province

A team of scientists has officially confirmed the discovery of the Jinlin crater, a remarkably well-preserved impact structure located in Guangdong Province, China. Nestled on a hillside near Zhaoqing City, specifically in Deqing County, this massive crater measures between 820 and 900 meters in diameter and reaches a depth of approximately 90 meters. Its formation dates back to the early-to-mid Holocene epoch, roughly 11,700 years ago, making it the largest known impact crater from this geological period on Earth.

The discovery marks a significant milestone, as it is the first confirmed impact crater in southern China and only the fifth in the entire country. Previously, Russia's Macha crater, with a diameter of 300 meters, held the record for the largest Holocene impact structure.

Scientific Confirmation and Impact Details

The research, led by Ming Chen from the Centre for High Pressure Science and Technology Advanced Research in Shanghai and affiliated with the China Academy of Engineering Physics (CAEP), involved extensive field studies and laboratory analyses. The definitive evidence for the crater's extraterrestrial origin comes from the presence of planar deformation features (PDFs) found within quartz fragments in the granite layers. These microscopic characteristics are geological fingerprints of impact events, forming under extreme pressures ranging from 10 to 35 gigapascals, conditions that cannot be generated by Earth's own geological processes.

Scientists have determined that the impactor was a meteorite, ruling out a comet, which would have created a crater at least 10 kilometers wide. The energy released by the impact is estimated to be equivalent to 600,000 tons of TNT, a force comparable to 40 Hiroshima-sized atomic bombs. The precise composition of the meteorite, whether iron or stone, is still under investigation.

Exceptional Preservation and Future Implications

One of the most surprising aspects of the Jinlin crater is its remarkable state of preservation. Despite Guangdong Province's climate, characterized by regular monsoons, heavy rainfall, and high humidity—conditions that typically accelerate erosion—the crater remains largely intact. This preservation is attributed to its location within a thick weathering crust atop granite, which protected its structure from the elements.

The findings, published in the journal Matter and Radiation at Extremes, challenge previous assumptions about the frequency and scale of recent impacts on Earth. As lead author Ming 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.' The Jinlin crater provides invaluable data for understanding Earth's impact history and the distribution of small celestial objects, particularly in warm and humid tropical and subtropical regions where such structures are rarely preserved.