Meteorite crater discovered in southern France
(ORDO NEWS) — Countless meteorites have fallen to Earth in the past and have shaped the history of our planet. It is assumed, for example, that meteorites brought with them most of the water.
The extinction of the dinosaurs could also have been caused by the fall of a very large meteorite.
Meteor craters that are still visible today are rare, because most of the traces of celestial bodies have long since disappeared. This is due to erosion processes and plate tectonics.
The Earth Impact Database lists just 190 such craters around the world. Only three were previously known in all of Western Europe: Rochechouart, Nördlinger Rice and Steinheim.
Geologist and cosmochemist Professor Frank Brenker of the Goethe University Frankfurt is convinced that a new meteorite crater will add to this list.
While on vacation, the Domaine du Météore winery caught his eye. One of the vineyards is located in a round hollow with a diameter of about 220 meters and a depth of 30 meters.
The winery’s owners use the hypothesis that this is an impact crater as an advertisement for their wine.
Frank Brenker explains: “Craters can form in many ways, and meteorite craters are indeed very rare.
However, I have found various other interpretations of how this depression might have formed to be unconvincing from a geological point of view.”
That’s why Brenker and his wife collected rock samples for analysis in the lab. They did find signs of an impact crater.
Brenker says: “Microanalysis has shown that the dark-colored layers in one of the shales, which usually just contain a higher percentage of mica, may be impact veinlets formed as a result of crushing and destruction of the rock, which in turn could be caused by impact.”
Brenker invited his colleague Andreas Junge, a professor of applied geophysics, and a group of students to the south of France to study the crater in detail.
hey found that the Earth’s magnetic field in the crater is slightly weaker than in the surrounding area.
This is typical of impact craters because the impact shatters or even melts the rock, which can thus contribute less to the Earth’s magnetic field.
Using strong magnets attached to the plate, the researchers also found tiny balls of iron oxide up to one millimeter in diameter.
Such balls have already been found in other impact craters. Later laboratory analysis showed that the local rocks also contained iron with nickel, and contained a core of minerals typical of the crater environment.
In addition, the researchers found numerous impact microdiamonds formed due to the high pressure during the meteorite impact.
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