The Eye of Sahara desert or Richat structure .
The eye of Sahara desert is also known as Richat structure. The Richat structure is near to Ouadane, west-central Mauritania. The formation stretches across a 40 kilometer-wide region of the desert in the nation of Mauritania. The Eye resembles a blue bullseye and is located in the Western Sahara. It is visible from space and has been used as a visual landmark by astronauts. Geologists believe that the Eye’s formation began when the supercontinent Pangaea started to pull apart.
The carbonatite rocks have been dated as having cooled between 94 and 104 million years ago. A kimberlitic plug and several sills have been found within the northern part of the Richat Structure. The kimberlite plug has been dated to around99 million years old.
The molten rock also dissolved limestone near the center of the Eye, which collapsed to form a special type of rock called breccia. A little after 100 million years ago, the Eye erupted violently. That collapsed the bubble partway, and erosion did the rest of the work to create the Eye of the Sahara that we know today.
Coordinates of Sahara Desert are: 21.1269 N, 11.4016 W
This prominent circular feature in the Sahara desert of Mauritania has attracted attention since the earliest space missions because it forms a conspicuous bull’s-eye in the otherwise rather featureless expanse of the desert. Described by some as looking like an outsizes fossil in the desert, the structure, which has a diameter of almost 30 miles, has become a landmark for shuttle crews. Initially interpreted as a meteorite impact structure because of its high degree of circularity, it is now thought to be merely a symmetrical uplift that has been laid bare by erosion. Paleozoic quartzites form the resistant beds outlining the structure.
Richat Structure. … The Richat Structure is an eroded rock formation spread in a circular format, found in the country of Mauritania in the Western Sahara, in Africa. The ‘Richat Structure’ is also known as the ‘Eye of the Sahara’, ‘Eye of Africa’, ‘blue eye of Africa’, ‘Earth’s bulls-eye’ and the ‘Guelb er Richat’.