Oasis
Key facts
- Country
- Libya
- Diameter
- 18 km
- Age
- less than about 120 million years
- Location
- 24.58° N, 24.40° E
A ring of sandstone hills and ridges in the Libyan Desert, south-eastern Libya. The central rings, about 5 km across, are clearest on satellite images.
Oasis is an eroded impact structure in the Libyan Desert of south-eastern Libya, about 80 km south of the smaller BP structure. Estimates of its original size range widely; it is often given as about 18 km across.
Discovery. Oasis was noticed in 1967 on aerial and space photographs of the Sahara, together with BP. It was named after the Oasis Oil Company, which was exploring the region.
What it hit. The impactor struck the Nubian Sandstone, a thick sequence of Cretaceous sandstones covering much of the eastern Sahara. Erosion has removed the upper part of the crater, leaving a central uplift of sandstone surrounded by rings of ridges.
Proof of impact. Geologists found shatter cones, cone-shaped fractures produced only by shock, and quartz with microscopic shock features in the central uplift. The structure was accepted as an impact structure in the 1970s.
Age. Like BP, Oasis must be younger than the Nubian Sandstone it struck, so less than about 120 million years old. Its exact age is unknown.
Libyan desert glass. Oasis was once suggested as the source of Libyan desert glass, a yellow natural glass found in the Great Sand Sea of western Egypt. Chemical studies have not supported this link, and the glass's origin is still debated.
Why it matters. Oasis and BP are among the few impact structures known in the eastern Sahara, a vast desert that has been little explored. The impactor is unknown.
Did you know?
Oasis was named after an oil company exploring the region.
It was once suggested as the source of Libyan desert glass, an idea chemistry does not support.
It lies about 80 km south of the BP structure.