Mysterious circles in the Sahara Desert

This ring structure Richat (Guell-Riyadh Richat) in the Sahara Desert near the Mauritanian town of Ouadane. Richat structure - geological formation, the most ancient ring is 500-600 million years old. Richat like a ring formation observed on the surface of the moon, Mercury and other bodies in the solar system. It was once thought that the ring structures - a meteoritic crater. Crater gradually filled with sediment and after millions of years on this site are formed like a giant saucer Richat. But studies have shown that this is not so.







The origin of the vast number of ring structures, including the structure Richat, can not explain the fall of meteorites, since they do not consist of one ring, and the ring of several tiers. To explain such a stacked, it must be assumed that in the same place more than one meteorite fell, and several meteorites about the same size. Because this love of meteorites to the same places is unlikely, it is believed that the ring structures are the result of the erosion of layered rocks.



However, even this does not explain almost perfectly round shape of the structure Richat.