Discover the Natural Stone Wonders: Richat Structure or the Eye of the Sahara

When you travel out into space to other galaxies, remember that Earth is following you all the way. As you look back, you will see from the heart of the desert, the 'Eye of the Sahara' staring at you, simply and directly, with no decoration or enmity.

The "Eye of the Sahara" seen up close

The 'Richat' structure, the name by which the 'eye' is known in the world of geology, appears as an enormous ellipse (40 km diameter) in the Adrar Plateau of Mauritania. Associated with a geological dome, the structure is made up of rocks of different ages and compositions, the oldest one from the Proterozoic, around 600 million years ago. The rocks are laid in concentric layers:  magmatic rocks from the granite family (rhyolite, gabbro, kimberlite) in the interior, a sedimentary rock similar to conglomerates (breccia) in the center, with a disc-shaped look, 40 m diameter, and several meters thick at the edges.

Sedimentary rocks lie on the outside. The youngest of the old ones appears to be a sandstone (natural sandstone), around 450 million years old. The sedimentary rocks appear as accumulations 3-4 m thick. There are also deposits of fine-grained gravel and sandstone, where freshwater fossils dating back 15,000 years have been found. Artifacts also show that the area was used as a hunting ground, plus a stone tools manufacturing area.

Where does "Sahara Eye" come from?

The appearance of the Richat structure impresses by measure. Let's now see what is so sensational that the structure was chosen by the International Union of Geological Sciences as one of the top 100 geological sites on Earth in terms of scientific importance. While opinion is unanimous on the breathtaking beauty of the volcanic and sedimentary rocks, organized in rings and seemingly escaping from beneath the sand, the origin of the composition of the 'Eye' remains one of the mysteries. The most sensational theory is that the 'Eye of Sahara' is a relic of ancient Atlantis. In his "Dialogues", Plato describes Atlantis as a city built on rings of land, bordered by rings of water, alternating on an area almost similar to what we know today if we refer to the central ring, which is 23.5 km in Plato's work, as it is today. There are also similarities between the environment in which Atlantis would have been, as an island, and today.

In addition, red, white, and black stones are found in the area of the Richat structure, just like those from which the walls of the ancient lost city were built. Similarly, Mauritania mines iron, copper, and gold ores, these metals are believed to have existed in abundance in Atlantis. In terms of location, the 'Eye of the Sahara' appears to overlap the ancient city, about 700 km south of the Atlas Mountains. The first king of Mauritania is said to have been Atlas, a name also mentioned by Plato in his writings on the kings of Atlantis. Some maps locate people called 'Atlanteans' on the territory of today’s Mauritania. A possible contradiction between the warm climate of Atlantis, with abundant vegetation and fauna, and that of the present-day Sahara is rejected, judging by the proof of the Sahara being green (around 5000 years ago), with whale bones and fossil shells, discovered in the desert, among other things. On the other hand, some consider Atlantis to be a figment of Plato's imagination. Other scholars believe that the real location of the ancient city would be the area in front of the Pillars of Hercules (Strait of Gibraltar). Even more acute is the mismatch of circumstances that could make possible the sinking conditions of Atlantis in the location of the Richat structure, an area 400 m above sea level and some 500 km inland.

What tectonic movements and how much water would have to exist for Atlantis to sink in a day and night? With so many pros and cons, the mystery doesn't seem to be easy to solve. Another view of the origin deems the Richat structure as an ancient mine. This theory is refuted by the size of the supposed quarry, but also by its shape, a geological dome instead of a depression, as would be natural for a mine. Even more outlandish is the myth that the 'Eye of Sahara' is a landing ground for alien ships.

However, besides these hypotheses, there are also scientific ones, such as that the Richat structure is a crater left over from the impact of a meteorite. However, the impact theory is dismissed due to the lack of specific rocks in the crater. The idea of a volcanic eruption in ancient times, resulting in the 'Eye of the Sahara', was then advanced. The magmatic rocks in the composition provided concrete evidence for this, but the lack of volcanoes in the area also makes it less probable.

Richat structure in pragmatic version

Current theories claim that the Richat structure formed about 100 million years ago when the continent of Pangaea fractured. The idea is based on a relative proximity to the intersection of the African and South American plates. Magma from deep below tried to surface, was trapped and only succeeded in lifting the crust, forming the Richat geological dome. The concentric circles come from fractures in the crust that occurred during uplift. The rest is the result of millennia of erosion.

A cramp of solitude

Today, this theory seems to be embraced by scientists, but lack of funding and working conditions make research in the area virtually impossible. However, nature is relentless and continues her attempt of permanently 'blinding' the 'Eye of the Sahara' so that one day, when you cross the galaxies again, the Earth will no longer follow you, and you will be free. And with yourself!