The Richat Structure or Eye of the Sahara or Earth

Eye of the Sahara ? Mauritania

The Eye of the Sahara is a magnificent landform located in the southwestern area
of the Sahara desert. Geologists originally thought the formation was crated when
a meteorite hit the earth, but now believe it was caused by erosion. Still, the
massive 30 mile diameter and the fact that it has a circular shape makes the formation
quite a mystery.

This spectacular landform in Mauritania in the southwestern part of the Sahara desert
is so huge with a diameter of 30 miles that it is visible from space. Called
Richat Structure --or the Eye of the Sahara-- the formation was originally thought to
be caused by a meteorite impact but now geologists believe it is a product of uplift
and erosion. The cause of its circular shape is still a mystery.

The part of the sedimentary rock corresponding to the white of the eye is a plateau
standing some 200 m above the sand desert. The Richat Structure corresponding to the
iris of the eye lies in a depression, and the peak of the outer rim is 485 m above sea
level. The Richat Structure consists of Early Paleozoic rocks, some 600 million years old.
Around the center, rocks resistant to weathering and erosion (purple and blue-green part)
make 100 m high ridges, and nonresistant rocks (yellow and brown part) form valleys. These
features alternate and are concentric.