Certain reliefs tell a story that no archive has preserved. When land shapes resist conventional explanations, geologists know that another scenario is worth considering. A vast depression, located in the subtropical hills of Guangdong, today reveals precise clues of an ancient extraterrestrial shock. This impact crater in China could well rewrite a forgotten part of recent geological history.
When natural depression reveals a forgotten story
At first glance, the Jinlin Basin could pass for a simple natural formation. Located in the subtropical hills of Guangdong province, southern China, it blends into a dense and green landscape. However, its dimensions, its slightly elliptical shape and its inclination of 13° towards the southwest intrigue geologists. This unusual relief extends over nearly 900 meters in diameter and has an apparent depth of 90 meters. The site is also distinguished by an unexpected phenomenon. Despite climatic conditions favorable to erosion (annual precipitation exceeding 1,500 mm, constant heat and high humidity), its edges are still well preserved.
The singularity of this depression does not stop at its state of conservation. It rests on a granite base dating from the Cretaceous, covered with a thick weathered crust of up to 80 meters. This granite mantle transformed into friable soil is, in general, unfavorable to the preservation of ancient structures. However, in this area subject to landslides and frequent water erosion, the Jinlin site has resisted. This topographic anomaly first aroused curiosity, before becoming the center of an in-depth geological investigation.
How Researchers Confirmed an Impact Crater in China
Behind the apparent banality of the site, the clues accumulate and lead to a striking revelation. It was not satellite surveys or aerial photos that made the decision, but the careful study of quartz grains taken from the crater floor. Chinese geologists have detected precise characteristics, called “PDFs” (planar deformation features), in more than fifty samples. These internal microstructures only form under extreme pressures, typical of a meteorite impact. They represent an indisputable signature of a very high speed shock, as explained in the study published in Matter and Radiation at Extremes.
The researchers then attempted to estimate the age of the event from the rate of chemical weathering of the local granite. The latter is eroding at a rate of approximately 0.038 mm per year. However, the fragments found on the surface, particularly those less than 30 cm, are still intact or very little altered. This observation suggests a relatively recent impact. The team thus proposes a dating located between the beginning and the middle of the Holocene, a geological period that began around 12,000 years ago. But this estimate remains conservative. Experts like Mark Boslough, cited in Scientific American, point out that only isotopic dating by radioactive decay (notably that of argon) would make it possible to decide, although it is long and expensive.
What this discovery changes for research in Asia
With its 900 meters in diameter, Jinlin greatly outclasses other impact craters known for this period. Until now, structures dated to the Holocene generally did not exceed 300 meters. The discovery of Jinlin therefore constitutes a major milestone for the study of recent impacts. It also calls into question a well-established idea. That according to which tropical regions, strongly altered by the elements, would be incapable of preserving the marks of such events.
This crater thus becomes the first of its kind officially confirmed in southern China, while only four others had been identified in the country, all located in the northeast. It opens a new field of scientific exploration for southern areas, long considered unsuitable for the detection of similar structures. Its existence, preservation and probable extraterrestrial origin call for revisiting other still unexplained geological formations in the region. Because it is perhaps not an isolated crater, but the beginning of a catalog to be reconstructed.
With an unwavering passion for local news, Christopher leads our editorial team with integrity and dedication. With over 20 years’ experience, he is the backbone of Wouldsayso, ensuring that we stay true to our mission to inform.
