Richat Structure

The Richat Structure is a circular rock formation on the Adrar Plateau in Mauritania that measures roughly 40 kilometers across. Concentric rings of sedimentary layers in varied colors and textures form the visible bands of this natural feature.

French explorer Théodore Monod first documented this formation during the 1930s and sparked decades of scientific study. Geologists initially debated a possible meteorite impact but later determined that erosion exposed the circular layers over time.

Berber herders cross the area with camel caravans and use the circular formation as a landmark when traveling through the desert. The local name tagense refers to the round opening of leather water bags that nomads carry at wells.

The closest settlement is Ouadane, and travelers need vehicles equipped for desert terrain along with ample water supplies to reach the site. Navigation with GPS is necessary because no marked paths cross the sandy plains.

A megabreccia core sits at the center and is surrounded by alternating bands of quartzite, limestone, and crystalline rocks. Astronauts have used this formation for decades as a recognition exercise for surface structures because it is clearly visible from orbit.

Location: Ouadane

Elevation above the sea: 423 m

Address: وادان, Mauritania

Website: https://earthobservatory.nasa.gov/images/92071/richat-structure

GPS coordinates: 21.12400,-11.40200

Latest update: December 14, 2025 19:11