Aouelloul
Key facts
- Country
- Mauritania
- Diameter
- 390 m
- Age
- 3.1 ± 0.3 million years
- Location
- 20.25° N, 12.68° W
A small, round crater about 390 m across with a raised rim of sandstone, in the desert of the Adrar region, Mauritania. Pieces of dark impact glass lie around it.
Aouelloul is a small, simple impact crater about 390 m across in the Adrar region of the Sahara, in Mauritania. It is best known for the dark glass scattered around it.
What can be seen. The crater is a bowl with a raised rim of upturned sandstone layers, partly filled with wind-blown sand. In the dry desert, its shape is well preserved.
What it hit. The impactor struck sandstones of early Palaeozoic age.
Aouelloul glass. Around the crater lie pieces of glass, formed when the impact melted the sandstone and threw the melt into the air. Because they formed in the same way as tektites, natural glass objects thrown from impact craters, they are sometimes called Aouelloul tektites, although they were not thrown far. The glass is the main evidence that the crater was made by an impact rather than by erosion or volcanic activity.
Age. Dating of the glass gives an age of about 3.1 million years, in the Pliocene, with an uncertainty of about 300,000 years.
A meteorite nearby. In 1973 an iron meteorite, named Zerga, was found just outside the crater rim. Scientists are not sure whether it has anything to do with the crater.
Why it matters. Aouelloul shows how much a small crater can reveal through its glass, and it lies in the same region as the Tenoumer crater. The impactor is unknown.
Visiting. The crater lies in remote desert. Travel with local guides and carry plenty of water.
Did you know?
Glass formed by melting sandstone lies scattered around Aouelloul.
An iron meteorite was found just outside its rim in 1973, but may be unrelated.
The crater is about 3.1 million years old.