The Richat Structure, also known as the Blue Eye of the Sahara, is a geological formation in the Sahara Desert.
The formation spans a 40-kilometer-wide area in Mauritania. It was first photographed by Gemini astronauts in the 1960s, who used it as a landmark to track the progress of the opening sequences. Later, the Landsat satellite captured additional images and provided data on the formation’s size, height, and extent.

Geologists initially thought the Eye of the Sahara was a blow crater formed when a space object collided with the surface. Long studies of rocks within the structure, on the other hand, show that their origins are entirely World-based. The Richat Structure is a 40 km diameter light elliptical dome that has been deeply eroded (25 ml). The sedimentary rock at this dome ranges from the Late Proterozoic in the dome’s center to the Ordovis sandstone. This structure’s sedimentary rocks run out at 10-20 °. The high puffy circular cuestas are the result of differential wear of resistant quartzite layers. The center is made up of a siliceous breeder with a diameter of at least 30 kilometers (19 miles).

A variety of intrusive and extrusive igneous rocks are exposed within the Richat Structure’s interior. Rhyolitic volcanic rocks, gabbros, carbonatites, and kimberlites are among them. The rhyolitic rocks are made up of lava flows and hydrothermally altered tuffaceous rocks from two distinct eruptive centers that are thought to be the eroded remains of two maars. The gabbroic rocks form two concentric ring dikes, according to field mapping and aeromagnetic data. The inner ring dike is about 20 meters wide and is located about 3 kilometers from the Richat Structure’s center. The outer ring dike is approximately 50 m wide and is located approximately 7 to 8 km from the structure’s center.Within the Richat Structure, 32 carbonatite dikes and sills have been mapped. The dikes are typically 300 meters long and 1 to 4 meters wide. They are made up of massive carbonatites that are mostly free of vesicles. The carbonatite rocks cooled between 94 and 104 million years ago, according to dating. Within the northern part of the Richat Structure, a kimberlitic plug and several sills have been discovered. The kimberlite plug is approximately 99 million years old. These intrusive igneous rocks are thought to be evidence of the presence of a large alkaline igneous intrusion that currently underpins the Richat Structure and created it by uplifting the overlying rock.

Volcanic activity from deep beneath the Earth’s surface lifted the entire landscape around the Eye millions of years ago. These areas were not deserts as we know them today. They were most likely much more temperate, with plenty of flowing water. During the temperate period, layered sandstone rocks were deposited by blowing winds and on the bottoms of lakes and rivers. The overlying layers of sandstone and other rocks were eventually pushed up by the subsurface volcanic flow. Wind and water erosion began to eat away at the domed layers of rock after the volcanism subsided. The area began to settle and collapse in on itself, resulting in the roughly circular “eye” feature.

The ancient rocks within the Eye of the Sahara have revealed information about its origins to researchers. The Eye’s formation began when the supercontinent Pangaea began to separate. As Pangaea broke up, the waters of the Atlantic Ocean began to flow into the region. While Pangaea was slowly separating, magma from deep within the Earth’s mantle began to push up, forming a circle-shaped rocky dome surrounded by layers of sandstone. The igneous rocks and sandstones were eroded, and as the dome subsided, circular ridges were left behind, giving the Richat Structure its sunken circular shape. The eye is now slightly sunken below the level of the surrounding landscapes

How do I get to the Sahara Eye?

The Western Sahara no longer has the temperate climate that existed when the Eye formed. It is possible to visit the dry, sandy desert that is home to the Eye of the Sahara, but it is not a luxurious trip. Travelers must first obtain a Mauritanian visa and locate a local sponsor. Tourists who have been admitted are advised to make local travel arrangements. Some entrepreneurs provide visitors with a bird’s-eye view of the Eye by offering airplane rides or hot air balloon rides over it. The Eye is located near the town of Oudane, which is a short car ride away, and there is even a hotel inside the structure.