Tuesday, December 9, 2008

Spectacular formation remains a puzzle

The Richat Structure, Oudane, Mauritania, is not really a structure but a huge circular formation (50 km in diameter - 30 miles), that resembles an eye when looked upon from space. Originally thought to be a crater, this volcanic dome is most likely a product of erosion, an ancient geological artifact in the middle of featureless Maur Adrar desert, in Africa's Western Sahara. The earliest space missions used it as a landmark, the adventurous 4x4 enthusiasts consider it to be their playground, and scientists are still debating its origin.
clipped from maps.google.com
clipped from maps.google.com
The meteorite impact theory could not explain the flatness of the "crater"'s floor, so the most accepted explanation is the erosion of the initial volcanic dome, which gradually peeled away the layers of rock, creating the present onion-like form.
Johnnie Shannon image-enhanced the satellite image, clearly showing an eroded circular anticline (structural dome) of layered sedimentary rocks:
there is also a hotel smack in the middle of the Richat Structure
 blog it

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