Did you know North Dakota is home to an ancient impact crater? Geologists, and many in the oil industry, have known about Red Wing Crater for decades, but I didn’t know anything about it until I searched “North Dakota impact craters” on a whim one day and discovered a fascinating story.

Roughly 200-million years ago, in the Triassic era, a meteorite impacted North America in the area that would become North Dakota, in McKenzie County, just a short distance west of the North Unit of Theodore Roosevelt National Park, or 15 miles southwest of Watford City.

Approximate location and size of Red Wing Crater, McKenzie County. Image/GoogleEarth

Unfortunately for photography hounds like myself, the Red Wing Crater is invisible from the surface, having long ago been buried by Jurassic-era rock, but it has been detected with seismic techniques. It is approximately 5 1/2 miles in diameter, and 6000 feet below ground. The location of the crater also happens to be ground zero for the North Dakota oil boom. Considering the number of oil industry folks in North Dakota, I might be the last dummy in the state to learn of the correlation between impact craters and oil exploration. Simply and unscientifically stated–if you find an impact crater of a certain age, there’s a good chance you’ll find oil.

Already having learned much from a simple search about North Dakota impact craters, I was even more interested to learn that the Red Wing crater is part of an even bigger hypothesis from geophysicist David Rowley of the University of Chicago.

In 1998, Rowley, with John Spray of the University of New Brunswick and Simon Kelley of Open University, proposed the Red Wing Crater may be just one of five craters (and possibly more) created in a multiple impact event. Taking the position of the continents 214 million years ago into account, and using the location of the craters, Rowley and his fellow researchers proposed several celestial objects may have impacted Earth in a fashion similar to the Shoemaker-Levy impacts on Jupiter in 1994.

The craters included in the multiple impact event hypothesis are Red Wing crater, Saint Martin crater in Manitoba, Manicouagan crater in northern Quebec, Rochechouart crater in France, and Obolon crater in Ukraine. Of these, Manicouagan crater is the most obvious, having created a ring-shaped lake.

Above: Manicouagan Crater, Quebec. Image/GoogleEarth

Above: St. Martin crater, Manitoba. Image/GoogleEarth

Above: Location of subterranean crater in Rochechouart, France. Image/GoogleEarth

Crater in Obolon, Ukraine. Image/GoogleEarth

One possible explanation for this multiple impact event, the probability of which is considered rare, reads as follows, from Rowley’s letter to Nature, 1998:

“A terrestrial multiple impact event resulting from the collision of several projectiles would appear to require a special situation, possibly involving the close fly-by, orbital capture and decay, and consequent clustered strike of a fragmented or weakly coherent comet or asteroid.”

In short, the object, possibly a comet or a loosely clustered asteroid, passed so close to Earth, it was captured, orbited the planet, then crashed to the ground in a series of multiple impacts.

Several other impact sites have been proposed as additional sites from the same event (a Wells Creek, Tennessee crater for example), and it has been theorized that additional impacts may have occurred in the prehistoric Tethys or Panthalassa oceans. The question of whether Rowley’s multiple impact event hypothesis is correct has yet to be settled.

I might not have every fact correct here, but I found the story of Red Wing crater very interesting. If you’re in the geology or oil industries and you know more about Red Wing crater, or you need to correct me somewhere, please feel free to add your comments.