Amguid
Key facts
- Country
- Algeria
- Diameter
- 450 m
- Age
- less than 100,000 years
- Location
- 26.09° N, 4.38° E
A sharp-rimmed, bowl-shaped crater about 450 m across and some 65 m deep in the Algerian Sahara, its floor covered by a flat, pale layer of hardened silt.
Amguid is a small, beautifully preserved impact crater in the Sahara Desert of central Algeria. It lies on a bare plateau of sandstone, and from above it looks almost as if it had been cut out with a giant pastry cutter: a near-circular bowl with steep sides and a flat, pale floor.
The impact. Amguid was formed when a meteorite struck the sandstone plateau, forming a crater about 450 m across and about 65 m deep. The rim is made of broken blocks of sandstone thrown up by the impact. The crater floor is covered by a flat layer of fine, pale silt, washed in by occasional rains and blown in by the wind, which has hardened into a crust.
The crater's age is not known precisely, but it is thought to be less than 100,000 years old. Its sharp rim and good preservation suggest it is geologically young.
Recognition. The crater was first spotted from the air in 1948 and described scientifically in 1969. Its circular shape, raised rim and broken rock all suggested an impact, and later studies supported an impact origin. Small, young craters like this are usually made by iron meteorites, which are strong enough to reach the ground at high speed, though little is known about the impactor at Amguid.
A simple crater. Amguid is a good example of a simple crater, a bowl-shaped crater without a central peak or rings. On Earth, craters smaller than about 2 to 4 km across usually form simple bowls, while larger craters collapse and form central peaks or rings. Amguid's well-preserved shape makes it a useful example for comparison with simple craters on the Moon and Mars.
The Saharan setting. Like Tenoumer in Mauritania and Kamil in Egypt, Amguid owes its excellent preservation to the dry climate of the Sahara. With little rain and almost no vegetation, erosion is very slow, and craters can survive for a long time without being worn away. The bare rock also makes them easy to spot from the air and in satellite images.
Why it matters. Amguid is one of the best-preserved small impact craters on Earth. It provides a clear example of how a small meteorite impact shapes the landscape, and it helps scientists understand the processes that form simple craters.
Visiting. Amguid is very remote, far from paved roads and towns. Reaching it requires a properly equipped desert expedition with experienced local guides. Travellers should check current safety advice and regulations before planning a trip.
Did you know?
Amguid's flat floor is covered by a pale crust of hardened silt.
Amguid was first spotted from an aircraft in 1948.
It is a textbook example of a simple, bowl-shaped crater.