Cloud Creek
Key facts
- Country
- United States
- Diameter
- 7 km
- Age
- about 190 ± 30 million years
- Location
- 43.12° N, 106.75° W
Nothing: the crater is buried about 1 km beneath the ranch land of central Wyoming.
Cloud Creek is a buried impact crater about 7 km across in Natrona County, central Wyoming, in the United States. It formed in the Late Triassic or Early Jurassic, roughly 190 million years ago.
Discovery. Like many buried craters, Cloud Creek was found by the oil industry. Seismic surveys in the 1990s showed a round structure with a central uplift, and wells drilled into it brought up broken rock. Study of the cuttings found shocked quartz with planar deformation features, the fingerprint of an impact, and the structure was described as an impact crater in the early 2000s.
What it hit. The impactor struck a sequence of Palaeozoic and early Mesozoic sedimentary rocks, including sandstones, siltstones and carbonates. The crater has a central peak and a collapsed rim, the form expected for a complex crater of this size in sedimentary rock.
Age. The youngest rocks disturbed by the impact are Triassic, and the oldest undisturbed rocks lying over the crater are Jurassic, so the impact happened between them. The usual estimate is about 190 million years, plus or minus about 30 million.
Why it matters. Cloud Creek shows how seismic surveys reveal craters that leave no trace at the surface. The impactor is unknown.
Did you know?
Cloud Creek was found by seismic surveys made in the search for oil.
It is buried about a kilometre beneath the surface.
The crater has a central peak, revealed only in seismic images.