New research finds that a circular depression is an old impact crater that holds a vineyard in a French winery.
The crater is located in the aptly named Domaine du Météore winery near Cabrerolles in southern France. The feature was first tentatively identified as a meteor crater in 1950. But a 1964 study argued against the identification because the crater had no raised rim and the scientists who authored the study could find no evidence. on the types of anomalies in the magnetic field that often exist. found at impact sites.
Now, a new examination of the site reveals a magnetic anomaly within the crater. In addition, rock fragments in and around the depression show that they are subject to a hard shock: There are pockets of melted and solidified rock, as well as microdiamonds that form under great pressure, researchers will report at the 54th Lunar and Planetary Science Conference (opens in a new tab) in The Woodlands, Texas, in mid-March.
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Domaine du Météore crater is relatively small for an impact crater, measuring just 656 feet (200 meters) across. The crater is about 98 feet (30 m) deep, with sides covered in scrub trees and a floor lined with neat Syrah grapes. Frank Brenker (opens in a new tab)geologist at Goethe University Frankfurt in Germany, and colleagues conducted the first comprehensive study of the crater over two separate visits, first taking rock samples for micro-analysis and then returning to analyze the crater’s magnetic field and other properties.
The researchers found several signs of impact, including dark-colored veins that may have been caused by a shock, as well as rock known as impact breccia, which is deformed and shows signs of being melted and reconstituted into a type of cement. The researchers also examined the soil for tiny impact spheroids, and found some tiny nodules rich in nickel and iron that are similar to those found in other impact craters.
“Such microspheres form by scraping the meteorite in the atmosphere or by impact alone, when a large part of the iron meteorite melts and then reacts with the oxygen in the air,” said Brenker in a. statement (opens in a new tab). These spheres contained microscopic flecks of diamond, which only form under high pressure.
Finally, the researchers conducted a magnetic survey of the crater and found that the magnetic field decreases closer to the center of the crater. This is also typical of impact craters, as the impact can destroy magnetic rocks or disrupt their magnetism by realigning the atoms responsible for creating the magnetic field in the first place, the researchers said.
The researchers also carried out a geoelectrical analysis of the crack, as the deformation of rocks during an impact may affect the way those rocks conduct electricity. That data is still being analyzed.
The new research did not estimate the age of the crater. However, the winery website (opens in a new tab) the impact crater is estimated to have occurred around 10,000 years ago.
Impact craters are rare on Earth as they are usually destroyed by erosion and shifting movements tectonic plates. The IS World Impact Database (opens in a new tab) only 190 confirmed craters are listed worldwide. Small craters like the one at the Domaine du Météore winery are likely to be destroyed; According to the new research abstract, there are only three known craters with a diameter of less than 984 feet (300 m).