Cloud Creek crater is an impact crater in Wyoming, United States.[1] The crater is located in Natrona County, about 48 miles northwest of Casper, near the center of a geological feature known as the Casper Arch.[2]:445 The Cloud Creek structure is circular with a current diameter of about 7 km, and it is buried beneath about 1200 m of Mesozoic rocks.[2]:445 The age of the structure is estimated to be 190 ± 20 million years, which means that it formed as the result of an impact during the early part of the Jurassic Period.[2]:445 This impact feature is not exposed at the surface, but it is known only through wells drilled for oil and gas. First reported by Donald Stone,[3] Cloud Creek is a circular structure documented using several 2D reflection seismic lines of fair to good quality, gravity, magnetic and borehole data.[2] The structure has a central core of brecciated, fractured and faulted rocks uplifted up to 520 m relative to the normal stratigraphy outside the structure. The core is surrounded by an annular trough and a detached fault-bounded rim anticline. The rim anticline defines the 7 km diameter of the structure. The structure was compressed and upthrown during the Laramide compression. Morphometric parameters of the structure are consistent with known impact structures. The core is associated with a positive gravity anomaly. Magnetic data could not be interpreted.[2]
The first published report of the Cloud Creek Structure was in 1985.[4] However, an impact origin was probably first proposed sometime after 1973 by a Casper geologist named Jack Wroble[3]:233 A total of ten wells have been drilled for oil and gas within the boundaries of the Cloud Creek structure between 1955 and 1999.[3]:221-225 Two wells have been drilled with the central peak, four wells within the encircling skirt, and four through the outer rim structure.
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