Tenoumer is an impact crater in Mauritania.
Tenoumer crater Wikipedia
The crater is located in the western Sahara Desert. It is 1.9 km in diameter and the age is estimated to be 21,400 ± 9,700 years old, placing it in the Pleistocene epoch.
The crater is exposed at the surface and is nearly circular. Edges of the crater rise up to 110 metres high above the base of the crater, but the bottom of the crater is covered with approximately 200 – 300 m thick layer of sediments.
Tenoumer crater has formed in gneiss and granite of Precambrian peneplain with a thin layer of Pliocene sediments (no older). The crater is believed to be caused by an impact event due to basement rocks found outside the crater. A volcanic origin was once theorized because of the discovery of basalt and rhyodacite outside of the crater basin, but current evidence clearly indicates an impact origin.