Saqqar
Key facts
- Country
- Saudi Arabia
- Diameter
- 34 km
- Age
- between about 70 and 410 million years
- Location
- 29.58° N, 38.70° E
Nothing: the structure is buried beneath younger flat-lying sediments in the desert of north-western Saudi Arabia.
Saqqar is a buried impact structure about 34 km across in north-western Saudi Arabia. It is the largest known impact structure in the Middle East.
Discovery. The structure was first noticed in seismic surveys made during exploration for oil and gas, which showed a buried round feature with a central uplift. In 2015 geologists published the first proof of its impact origin, using seismic profiles, gravity data and cores from six wells.
What it hit. The impactor struck a thick sequence of Cambrian to Devonian sedimentary rocks, mainly sandstones. The rebound of the crater floor raised a central uplift about 2 km high, surrounded by a ring of down-folded rock.
Proof of impact. Sandstone cores from the wells contain quartz grains with planar deformation features and planar fractures, as well as shocked feldspar and deformed mica. These features show that the rocks were subjected to shock pressures of about 5 to 15 gigapascals.
Age. The age is poorly known. The impact happened after the youngest rocks affected, about 410 million years old, and before the overlying undisturbed Cretaceous and Palaeogene sediments, about 70 million years old.
Why it matters. Saqqar shows how seismic data collected for oil exploration can reveal large impact structures even under featureless desert. The impactor is unknown.
Did you know?
Saqqar is the largest known impact structure in the Middle East.
Its central uplift rises about 2 km above the surrounding buried layers.
Its impact origin was proven in 2015.