The so-called Richat Structure is a geological formation in the Maur Adrar Desert in the African country of Mauritania. Although it resembles an impact crater, the Richat Structure formed when a volcanic dome hardened and gradually eroded, exposing the onion-like layers of rock.

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IG Type: 
Source: 
Landsat 7
JPG name: 
RICHAT
TIF name: 
RICHAT
Scale: 
1.7 miles (2.8km)