The crater is located in the western Sahara Desert. It is 1.9 km (1.2 mi) in diameter and its age was estimated to be 21,400 ± 9,700 years old but as of 2016, is thought to be ~1.57 Ma.[2]
The crater is exposed at the surface and is nearly circular. Edges of the crater rise up to 110 m (360 ft) high above the base of the crater, but the bottom of the crater is covered with an approximately 200 to 300 m (660 to 980 ft) thick layer of sediments.[3]
Tenoumer crater has formed in gneiss and granite of Precambrianpeneplain 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,[4] but current evidence clearly indicates an impact origin.[5]