Red Wing
Key facts
- Country
- United States
- Diameter
- 9 km
- Age
- about 200 ± 25 million years
- Location
- 47.60° N, 103.55° W
Nothing: the crater lies about 2 km below the badlands and prairie of McKenzie County, North Dakota.
Red Wing is a buried impact crater about 9 km across in McKenzie County, western North Dakota, in the United States. It is one of the best-known examples of an impact crater that became an oil field.
Discovery. In 1972 an oil well drilled in the area unexpectedly found oil in a thick column of broken rock at a depth of about 2 km. Seismic surveys then revealed a round structure with a central peak, rising hundreds of metres above its surroundings. Study of the cores found shatter cones and shocked quartz, and the structure was identified as an impact crater.
What it hit. The impactor struck a thick sequence of Palaeozoic and early Mesozoic sedimentary rocks of the Williston Basin, including limestones, dolomites and shales. The rebound of the crater floor lifted older layers in the central peak by hundreds of metres. Later sediments buried the crater.
Age. The youngest rocks affected are Permian or Triassic, and the oldest undisturbed rocks lying over the crater are Jurassic. The impact is usually dated to about 200 million years ago, plus or minus about 25 million.
Oil. The broken rock of the central peak forms a reservoir capable of holding a large amount of oil. The Red Wing Creek oil field has produced millions of barrels.
Why it matters. Red Wing helped show the oil industry that impact craters can create rich reservoirs. It has also been suggested as one of a chain of craters formed by a broken-up object about 214 million years ago, but its age is too uncertain to test that idea. The impactor is unknown.
Did you know?
Red Wing was discovered in 1972 when an oil well struck oil in broken rock.
Its central peak holds an oil reservoir.
The crater lies about 2 km underground.