Nestled on a hillside in Guangdong Province near Zhaoqing City, the Jinlin crater managed to hide in plain sight until researchers identified it as an impact structure.
Only about 200 confirmed impact craters exist worldwide, making each discovery scientifically valuable.
But this one stands out for its exceptional size and youth.
The crater formed during the Holocene epoch when the last ice age ended roughly 11,700 years ago.
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Based on measurements of nearby soil erosion, researchers estimate it was carved sometime during the early to mid-Holocene.
With a diameter between 820 and 900 metres and a depth of 90 metres, it dwarfs Russia's 300-metre Macha crater, previously the largest known Holocene impact structure.
Finding such a massive, well-preserved crater is surprising given the region's climate. Guangdong Province experiences regular monsoons, heavy rainfall, and high humidity, precisely the conditions that accelerate erosion and should have long ago obliterated any visible crater.
Yet the Jinlin crater remains remarkably intact, preserved within thick layers of weathered granite that protected its structure from the elements.
The evidence confirming its extraterrestrial origin lies in the details. Within the granite, researchers found numerous quartz fragments exhibiting planar deformation features and microscopic characteristics that serve as geological fingerprints of impact events.
"On Earth, the formation of planar deformation features in quartz is only from the intense shockwaves generated by celestial body impacts," - Ming Chen, lead author from the Centre for High Pressure Science and Technology Advanced Research in Shanghai.
These features form under extreme pressure between 10 and 35 gigapascals, far exceeding anything Earth's own geological processes can generate.
No volcanic eruption, earthquake, or tectonic movement creates such intense, focused shockwaves. Only the hypervelocity collision of an extraterrestrial object produces these telltale signatures.
The researchers have determined the impactor was a meteorite rather than a comet since a comet would have excavated a crater at least 10 kilometres wide.
However, they haven't yet established whether it was composed of iron or stone, and considerable work remains. But the discovery already challenges previous assumptions about the frequency and scale of recent impacts.
Earth's surface theoretically faces equal bombardment odds everywhere, yet geological differences mean impact evidence erodes at varying rates.
Some craters disappear entirely while others, like Jinlin, survive. This uneven preservation creates a skewed picture of our planet's impact history.
Confirmed craters cluster disproportionately in well-funded regions with active geological research programs, while this discovery in a remote, forested hillside suggests many more impact structures might await identification elsewhere.
As researchers continue investigating the Jinlin crater, it may reveal new insights into how frequently sizable space rocks strike our planet and what protects or destroys the evidence they leave behind.
This article was originally published by Universe Today. Read the original article.