The Eye of the Sahara, also called the Richat Structure, is a massive circular geological feature located deep in the desert of Mauritania, not far from the Canary Islands. It spans more than 50 kilometers across and was shaped by erosion and uplift, creating a dome that later wore down to reveal its rings.
At first glance it may resemble an impact crater created by a meteor. In reality it is a unique example of a crater-like structure formed by folding of rock layers exposed through geological processes and erosion, specifically a symmetrical anticline.
Among the planet’s most striking geological formations, the Eye of the Sahara invites exploration from both ground level and a bird’s-eye view. It has drawn keen interest from geologists who seek to understand the precise sequence of events that produced this feature.
Although the site lies in a remote and secluded part of the desert, it has long fascinated observers in space, where its round silhouette is most easily appreciated. The structure has become one of the most famous natural curiosities on Earth.
How was it formed?
The formation likely resulted from a folding process that created a symmetrical anticline. Folding occurs when tectonic forces push sedimentary rock from opposite sides, causing compression. Rock tends to bend when heated and becomes brittle when cooled. Upward folds are anticlines, while downward folds are synclines.
In 2014, an article in the African Journal of Earth Sciences proposed an alternative origin for the Eye of the Sahara. The authors suggested that volcanic rocks indicate a different path to the rings now visible. They proposed that molten rock rose to the surface before erosion sculpted the dome-like shape, and that movements related to the break-up of the supercontinent Pangea may have influenced these volcanic and tectonic processes.
The structure combines sedimentary and igneous rocks. Erosion reveals hydrothermally altered fine-grained rhyolite and coarse-crystalline gabbro in the surface layers. The rings host rocks that erode at different rates, creating varied colors and textures. Large fragments of sedimentary rock contribute to the mosaic of angular, multicolored pieces that define the scene.
The Eye of the Sahara has been recognized as one of the top 100 geological heritage sites by the International Union of Geological Sciences, highlighting its significance in global earth science.
Further reading includes scholarly work that synthesizes findings on doming and related structures in the region, offering a comprehensive view of how such features fit into broader tectonic narratives.
For additional context, this article relies on established geologic surveys and peer-reviewed studies, with notes to source material provided in the discipline’s literature and databases. [citation]